The essence of water
Unique Earth
Dec. 9, 2022
Embedded video, no copy made
Water is the most important substance on Earth. We are made of water, and need it to survive. Water keeps us clean and healthy. We use it to wash our clothes, our cars and our dishes. It fills our desert swimming pools, lakes and rivers.

Never are we more aware of how important water is when we don't have access to a safe, clean constant supply. But worldwide there are millions of people who don't because of social, economic and political inequities and climate change.

Science and technology have provided methods for measuring water shortages, for predicting weather events causing droughts and floods and for purifying and storing water for future use but they cannot replace human efforts required to implement them.

The story of water preservation and protection in Arizona began more than a century ago when farmers, politicians, water management groups, public utilities and consumer advocates recognized its importance and began working together to plan for Arizona's future water needs. Water now weaves through our state within the Salt River Project (SRP) lakes and reservoirs and through the Central Arizona Project (CAP) canal.

Arizona has been in the midst of a drought for more than two decades. Even though the water levels in our lakes and reservoirs have declined as the amount of groundwater has ebbed and flowed, our future water supply should be secure if we take care of it.

Before exploring this website, please review the information in the Site Notes section.


Blue Marble
Blue Marble
H. Schmitt and R. Evans
Apollo 17, NASA
Dec. 7, 1972
Wikipedia earth
public domain
Life on Earth depends on water. Nearly all living things need and use it. Water regulates body temperature, assists in nutrient absorption, helps fight off illness and does many other things to maintain the wellness of living creatures. [1],[2]

Water is also used in agriculture, transportation for moving goods across oceans and in rivers, as a universal solvent,water is capable of dissolving more substances than any other liquid for putting out fires and for hydroelectric powerthe use of flowing water to power a turbine to produce electrical energy production.

Water is far more. It is necessary for sustainable socio-economic development, human productivity, healthy ecosystems and a key factor in managing epidemics, famine, social inequality and political instability.[3]

The United Nations estimated that the world's population reached 8 billion on November 15, 2022. It took 12 years for the global population to grow from 7 to 8 billion. It is expected to reach 9 billion by 2037, meaning that the planetary population is increasing, but at a declining rate.[4]

But countries with the highest fertility rates are usually those with the lowest per capita income, meaning that global population growth is now concentrated in the world's poorest countries. Most are in Africa where development of water systems can't keep up with sustained rapid population growth.[4]

Rising per capita incomes create unsustainable patterns of production and consumption. Countries with the highest per capita incomes also produce the most greenhouse gases, causing drought and flooding and disproportionately affecting water supplies in poorer countries.[4]

Water resources require short-term and long-term management. Increased competition for water, pollution, technological breakthroughs, global warminga gradual increase in the overall temperature of the Earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, chlorofluorocarbons, and other pollutants and climate changea change in global or regional climate patterns, in particular a change apparent from the mid to late 20th century onwards and attributed largely to the increased levels of atmospheric carbon dioxide produced by the use of fossil fuels lead to stresses on, threats to and water imbalances among the hydrosphere,the combined mass of water found on, under, and above Earth's surface biosphere,the regions of the surface, atmosphere, and hydrosphere occupied by living organisms atmosphere,the layer of gases surrounding a planet or moon cryosphereportions of a planet's surface where water is solid, including sea ice, lake ice, river ice, snow cover, glaciers, ice caps, ice sheets, and frozen ground and lithosphere.the rigid outer part of the Earth, consisting of the crust and upper mantle

All citizens of planet Earth have a responsibility to care for our water by practicing water conservation, encouraging new water uses that improve standard of living and sanitation, and learning about this rare and precious resource.

On what date is World Water Day?

[1] Mayo Clinic. (Jul. 22, 2020). Water: Essential to your body.

[2] Silver, N. (Jun. 20, 2020). Why is water important? 16 reasons to drink up. Healthline.

[3] United Nations. (Jun. 20, 2020). Water facts.

[4] United Nations. (n. d.). Day of 8 billion.

Habitable Zone

Terrestrial planets: Mercury, Venus, Earth, Mars
Terrestrial planets: Mercury, Venus, Earth, Mars
Nov. 26, 2011
Wikipedia solar system
public domain
Our water resources are unique. Except for possibly Jupiter's moon EuropaEuropa
Sep. 7, 1996
Wikipedia Europa
public domain
which may have a global ocean surrounded by a layer of ice, and Saturn's moon EnceladusEnceladus
Oct. 28, 2015
Wikipedia Enceladus
public domain
with its ice-water geysers,a hot spring in which water intermittently boils, and emits a tall column of water and steam into the atmosphere no other body in our solar system is known to possess the vast water resources of planet Earth.

At approximately 150 million kilometers, Earth is the third planet from the Sun. We live in the habitable zone,also called the "Goldilock's zone," the orbital region around a star in which an Earth-like planet can possess liquid water on its surface and possibly support life where H2O can simultaneously exist in all three forms, as ice, liquid water and water vapor.[1]

Our neighbor Venus, the second planet from the Sun, at about 108 million kilometers, is surrounded by a thick carbon dioxideCO2, a colorless, odorless, incombustible gas atmosphere and sulfuric acida strong acid made by oxidizing solutions of sulfur dioxide clouds. It has a surface pressure 92 times that of Earth, and a temperature of 864oF (462oC). If Venus ever had water, it disappeared long ago as a result of Venus' runaway greenhouse effect. occurs when a planet's atmosphere contains greenhouse gases that block heat escaping from the planet, preventing the planet from cooling and from having liquid water on its surface[2]

Our other neighbor, Mars, the fourth planet from the Sun, at about 228 million kilometers, has a very thin carbon dioxide atmosphere and no surface water, although ice has been detected below its surface, where the pressure is less than 1% of that at Earth's surface.[3]

Phoenix,Phoenix Lander
Phoenix Lander
NASA/JPL/Corby Waste
Jan. 1, 2007
Wikipedia Phoenix spacecraft
public domain
Spirit,Spirit Mars Rover
Spirit Rover
Apr. 5, 2009
Wikipedia Spirit Mars Rover
public domain
Opportunity,Opportunity Mars Rover
Opportunity Rover
Oct. 28, 2015
Wikipedia Opportunity Mars Rover
public domain
and CuriosityCuriosity Mars Rover
Curiosity Rover
Oct. 7. 2015
Wikipedia Curiosity Mars Rover
public domain
are four of history's most successful Mars missions. Phoenix located ice near Mars' north pole.[4] Opportunity landed in a crater, where it found the mineral hematite,a common iron oxide black to steel or silver-gray, brown to reddish-brown, or red in color that usually precipitates from water and collect in layers at the bottom of a lake, spring, or other standing water which usually forms in water. Spirit found rocks ten times richer in magnesium and iron carbonates than any other Martian rocks previously found. These rocks formed when Mars was warm, wet, had neutral pHscale used to specify how acidic or alkaline a water-based solution is, acidic solutions have lower pH, and alkaline solutions have higher pH water and a thicker carbon dioxide atmosphere.[5]


Opportunity: NASA Rover Completes Mars Mission
NASA Mars Exploration Rovers
Feb. 13, 2019
Embedded video, no copy made
[1] NASA Solar System Exploration. (n. d.). Earth.

[2] NASA Solar System Exploration. (n. d.). Venus.

[3] NASA Solar System Exploration. (n. d.). Mars.

[4] NASA. (Dec. 11, 2019). NASA's treasure map for water ice on Mars.

[5] NASA. (n. d.). Mars Exploration rovers.

Origin and Structure

Earth`s structure
Earth`s structure
Jan. 18, 2013
Wikipedia mantle (geology)
CC BY-SA 3.0
Where did Earth get its water?

Water, as part of Earth's hydrosphere,the combined mass of water found on, under, and above Earth's surface is formed from hydrogen and oxygen, two of the three most abundant elements in the universe. Throughout Earth's history, water has been a central link among Earth's atmosphere,the layer of gases surrounding a planet or moon cryosphere,portions of a planet's surface where water is solid, including sea ice, lake ice, river ice, snow cover, glaciers, ice caps, ice sheets, and frozen ground biospherethe regions of the surface, atmosphere, and hydrosphere occupied by living organisms and lithosphere.the rigid outer part of the Earth, consisting of the crust and upper mantle Interactions between water and land formed oceans, rivers, lakes, and streams through erosion, providing life a place to thrive for millions of years.[1]

In space, ice acts as a surface for the formation of organic compoundsa chemical compound in which carbon atoms are are linked to hydrogen, oxygen or nitrogen atoms that are precursors for life and that eventually became incorporated into cometsa celestial object consisting of a nucleus of ice and dust which develops a gas tail that points away from the Sun and asteroidsa small rocky body orbiting the Sun in the early Solar System.[2]

Scientists speculate that most of Earth's water arrived with extraterrestrial assistance, not from aliens, but from comets and asteroids. By counting the numbers of protonsa positively-charged subatomic particle in atomic nuclei and neutronsa neutrally-charged subatomic particle in atomic nuclei in water molecules they can determine whether those molecules have the usual 10 protons and 8 neutrons, or if those molecules are water isotopesone of two or more species of atoms of a chemical element with the same atomic number and position in the periodic table and nearly identical chemical behaviour but with different atomic masses and physical properties with a different number of protons.[3]

The proportion of deuteriumisotope of hydrogen with a nucleus consisting of one proton and one neutron found in Earth's water, in comet 46P/Wirtanen46P/Wirtanen
S. Mandrel
Dec. 12, 2018
Wikipedia 46P/Wirtanen
CC BY-ND 4.0
and in Vesta,Vesta
Aug. 2, 2011
Wikipedia 4 Vesta
public domain
a large asteroid orbiting between Mars and Jupiter, are about the same, meaning that both comets and asteroids may have contributed to Earth's water.[3]

A 2023 study, based on exoplaneta planet that orbits a star outside of the solar system data, speculates that chemical reactions that occurred during Earth's formation could have produced enough water to fill Earth's oceans Hydrogen has been found in the atmospheres of exoplanets similar to Earth, implying that our planet may have also had that element in abundance.[4]


Universe Element Percentages
atomic number↕ element symbol↕ element↕ percent↕ abundance % in
Earth's crust
1 H hydrogenexplosive, found in the atmospheres of Jupiter and Saturn 73.9 0
2 He heliumvery stable, also found in the atmospheres of Jupiter and Saturn 24.0 0
8 O oxygenalso called dihydrogen monoxide 10.4 46
6 C carbona common element of all known life 4.6 0
10 Ne neoninert, doesn't combine with other elements 1.34 0
26 Fe ironcommon in meteorites called siderites 1.09 5.6
7 N nitrogenmakes up about 78% of Earth's atmosphere 0.96 0
14 Si siliconwidely distributed in space in cosmic dusts, planetoids, and planets as forms of silica 0.65 28
12 Mg magnesiumproduced in large, aging stars 0.58 2.4
16 S sulfuralso called brimstone 0.44 0

[1] Farmer, J. D. (n. d.). Astrobiology: Water and the potential for extraterrestrial life. Water Encyclopedia.

[2] Mottl, et al. (Dec. 21, 2007). Water and astrobiology. Geochemistry, 67(4), 253-282.

[3] Stierwalt, S. (Oct. 6, 2019). How did water get on Earth? Scientific American.

[4] Timmer, J. (Apr. 12, 2023). Chemical reactions on the early Earth may have formed its ocean. Ars Technica.,density%20of%20the%20Earth's%20core.

Earth History

Earth has changed significantly during its 4.6 billion-year history. There have been long periods of stability, interrupted by violent events and temperature changes causing mass extinctions.refers to an event when many species die off in a relatively short period of geological time [1]

Snowball Earth artist rendering
Snowball Earth artist rendering
O. Kuznetsov
Apr. 28, 2020
Wikipedia snowball earth
CC BY-SA 4.0
When geologists name an epoch, they determine a geographic location that marks its start, called a global stratotype section and point (GSSP)geographic location that marks a geologic time period, characterized by certain fossils, the spread or extinction of certain species, a particular ice core sediment or a chemical or radioactive residue, sometimes referred to as a golden spike. Researchers try to identify features that sites from that period have in common. The key features can include specific minerals, fossils, geomagnetic reversalswhen a planet's magnetic north and magnetic south switch positions and sediments.[5]

Scientists speculate that 770 million years ago the Earth may have been covered in ice, a period referred to as Snowball Earth. One theory states that sulfur gas particles, from large volcanic eruptions, were absorbed by the atmosphere, reacted with solar radiation and cooled the planet. These conditions may have caused an explosion of multicellular organisms.[1]

The Carboniferous period, about 350 million years ago, was known for marshy forest communities inhabited by ancestors of reptiles, mammals and amphibians. Permanent ice caps covered Earth's poles.[1]

About 305 million years ago, carbon dioxide levels increased, preventing heat from escaping the atmosphere. Earth warmed, dried and endured intense seasonal changes. Carboniferous rainforest plants suffered, leading to a change in plant and animal communities and the age of the dinosaurs.[1]

The Cretaceous-Paleogene extinction event occured about 66 million years ago, when an asteroid collided with Earth at Yucatán, Mexico. The collision created the Chicxulub crater.Chicxulub crater
Chicxulub crater
Feb. 1, 2000
Wikipedia Chicxulub crater
public domain

A huge cloud of ash, dust and other debris was absorbed by the atmosphere, blocking sunlight. Phytoplanktonplankton consisting of microscopic plants and plant photosynthesisprocess by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water stopped and dinosaurs disappeared.[1]

Animated Maps: Tectonic Plate Movement
Esri Geographic Information System
Nov. 20, 2019
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Permian-Eocene Thermal Maximuma short interval of maximum temperature aboout 55 million years ago lasting approximately 100,000 years during the late Paleocene and early Eocene epochs occured about 55 million years ago. Over 100,000 years, the planet slowly warmed by between 5Co and 8Co. (Degree changes are noted as Co or Fo while specific temperatures are noted as oC or oF.) One theory assumes that a volcanic eruption caused marine sediments to release methane.a powerful greenhouse gas and the simplest hydrocarbon, consisting of one carbon atom and four hydrogen atoms Oceans across the globe reached tropical temperatures, resulting in extinction of a significant amount of marine life.[1]

Scientists are debating on an official start of the Anthropocene, but some believe it began near the end of the 18th century when the industrial revolution began. Others claim that nuclear weapons testing in the 1950s and an acceleration of destructive human activity changed our planet.[7]

A decade of American and Australian dust storms, declining bald eagle populations, and the publication of Rachel Carson's Silent Spring in 1962, exposing the devastating use of pesticides, resulted in the 1972 ban of DDT.[7]

In 1979, David Attenborough's Life on Earth series brought distant wildlife and environments into the homes of 25 million television watchers.[7]

Reports by the International Union for Conservation of Nature (IUCN), the United Nations and increased worldwide media coverage began to educate the public about the devastating effects of climate change.[7]

Earth's Five Plus One Major Extinction Events[2]
event approximate time
in millions of
years ago
possible causes environment
Ordovician-Silurian 440 85
  • climatic shift caused sea temperatures to change, majority of ocean life died
  • rapid onset of mass glaciation covered the southern supercontinent, Gondwana
  • dramatic lowering of global sea level
  • cooling may have been caused by formation of North American Appalachian Mountains
  • large-scale erosion of silicate rocks is associated with greenhouse gas carbon dioxide removal from the atmosphere
  • toxic metal may have dissolved into ocean water during oxygen depletion
  • a supernova gamma-ray burst ripped a large hole in the ozone layer
  • massive volcanism
  • shallow waters filled with corals and shelled brachiopods
  • life started to spread and diversify
  • food chains were destroyed
  • decreases in reproduction
  • Late Devonian 365 75
  • nutrient-rich soil ran into world oceans, causing huge algae blooms, creating giant dead zones
  • algae stripped oxygen from water, suffocating marine life and damaging marine food chains
  • species unable to adapt to decreased oxygen and lack of food died
  • volcanic eruptions may have been responsible for decreasing ocean oxygen levels
  • animals began to evolve on land
  • most life swam through the oceans
  • plants evolved roots and created soil
  • Permian-Triassic 253 70
  • major volcanic eruptions, primarily in Siberia
  • large amounts of carbon dioxide released into the atmosphere, causing greenhouse effect heating Earth
  • weather patterns shifted
  • sea level rose
  • acid rainstorms
  • Pangaea may have created a global pool of stagnant water
  • decimated reptile, insect and amphibian land populations
  • increased levels of ocean carbon dioxide poisoned marine life, depriving them of oxygen-rich water
  • 14 million years were required for coral reefs to rebuild
  • Triassic-Jurassic 201 80
  • massive volcanic eruptions, in the area now covered by the Atlantic Ocean, may have released massive amounts of carbon dioxide
  • climate change and global temperature increases
  • melting ice, rising sea level
  • dinosaurs began to populate Earth
  • marine and land species extinction, including large prehistoric crocodiles and some flying pterosaurs
  • Cretaceous-Paleogene 66 75
  • an asteroid more than 8 miles (13 km) in diameter crashed into Yucatán, Mexico forming the Chicxulub crater
  • the impact forced tons of debris and dust into the atmosphere
  • temperatures decreased, creating a global winter
  • killed the dinosaurs, after a 100 million-year existence on Earth
  • plants couldn't absorb sunlight and died
  • most extinctions occurred a few months after the impact
  • some flying, burrowing and diving species survived, including birds
  • more than 10,000 existing species may descend from the survivors
  • Anthropocene[3], [4] 0.01 4.5 per year
  • human introduction of invasive species to fragile ecosystems
  • tons of greenhouse gases added to the atmosphere since the Industrial Revolution
  • term proposed in 2000 by Nobel Prize winning scientist Paul Crutzen
  • current extinction rate is 10 to 100 times higher than previous mass extinctions
  • as many as 25% of all species are threatened with extinction[6]
  • global increases in soil erosion caused by land clearing and soil tillage for agriculture
  • deforestation
  • massive species extinctions caused by hunting and natural habitat destruction
  • Sources:

    [1] National Park Service. (n. d.). A history of Earth's climate. Captain John Smith Chesapeake.

    [2] Dutfield, S. (May 17, 2021). The 5 mass extinction events that shaped the history of Earth - and the 6th that's happening now. LiveScience.

    If Venus had water, what made it disappear?
    [3] Lau, B. (Dec. 19, 2019). The Anthropocene extinction.

    [4] Ellis, E. (Sep. 3, 2013). Anthropocene. The Encyclopedia of Earth.

    [5] Curry, A. (Jun. 22, 2022). Humanity left an irreversable imprint upon Earth's rocks. Here's how. National Geographic.

    [6] Purvis, A. (May 22, 2019). How did IPBES estimate '1 million species at risk of extinction' in #GlobalAssessment Report. IPBES.

    Mesopotamia began by which rivers?
    [7] Weston, P. (Nov. 25, 2022). Humans v nature: Our long and destructive journey to the age of extinction. The Guardian.

    Water History

    About 10,000 years ago permanent, agrarian settlements relying on local water sources, were established. Clean water was necessary for humans, animals and plants to survive and maintain food sources.[1]

    Since the Bronze Age, between 3200 to 1100 BC, domestic wastewater was used for irrigation and aquaculture in China, Egypt, the Indus Valley, Mesopotamia and Crete.[2] Traces of wells, rainwater channels and toilets were discovered in these cities.[1] The growth of permanent settlements led to the development of collection systems for this wastewater and for stormwater.[2]

    During the late fourth millennium BC, walled cities in southern Mesopotamia, near the Tigris and Euphrates rivers, were established on intensive irrigation agriculture that required canal maintenance.[3]

    The Minoans developed advanced sewage systems to dispose of wastewater to rivers, the ocean, and agricultural land for irrigation and fertilization purposes.[2]

    Pont du Gard aqueduct in Roman Gaul
    Pont du Gard aqueduct in Roman Gaul
    B. L. Song
    Jun. 12, 2013
    Wikipedia aqueduct
    CC BY-SA 3.0
    Ancient Greek doctors recognized the importance of clear, clean, tasteless water and Romans discovered that water circulated through ceramic pipes, rather than lead, had fewer negative health effects.[1]

    Between 1000 BC to 330 AD, wastewater was used for irrigation and fertilization in areas surrounding important cities, including Athens and Rome.[2] Ionian philosophers recognized that all of Earth's water is recycled and reused and the existence of the water cycle and evaporation.[2]

    Sanitation systems arose in Great Britain, spread across Europe and arrived in the U.S. These systems limited the spread of water-borne diseases, including cholera, dysentery and typhoid fever that scientists discovered in water supplies.[1]

    Between 330 and 1400 AD in Medieval Europe water technology and knowledge made little progress because of frequent wars. Disease outbreaks were common and epidemicsa widespread occurrence of an infectious disease wiped out town and village residents. In Europe, about 25% of the population died due to cholera, plague, and other water born diseases due to unregulated waste disposal.[2]

    Modern chinampas
    Modern chinampas
    Sep. 20, 2006
    Wikipedia chinampas
    CC BY-SA 3.0
    Between 1200 and 1500 AD, innovative water reuse methods were developed and used in early Central and South America before colonization. One of these methods included chinampas, Mesoamerican floating gardens built over wetlands, marshes, shallow lakes or flood plains using sediments, manure, compost and vegetation debris.[2]

    The Aztec made other contributions to water resource planning including management of saline water and fresh water, control of the lake levels to avoid floods and management of urban wastewater and agriculture to increase food security.[2]

    Beginning in 1531, wastewater was used for crop production in Bunzlau, modern-day Poland, and later in Edinburgh, Scotland in 1650.[2]

    Sanitation practices re-emerged in the mid-nineteenth century following the great epidemics in several regions of the world and water filtering and chlorinationwater disinfection by adding chlorine were introduced into municipal water supplies.[2]

    By the mid-20th century, the health effects of biological hazards, including chemical and radioactive waste, were discovered, but not eliminated. About 10,000 people die every day from dysentery, cholera, and other diseases cause by unsafe water and inadequate sanitation. Most are members of marginalized groups, refugees and the poor.[1]

    About 80% of the world's wastewater and over 95% in some under developing countries is released into rivers and streams, where it is diluted and transported downstream or infiltrated into aquifers.a body of permeable rock which can contain or transmit groundwater[2]

    California's Santa Ana river drainage basin
    California's Santa Ana river drainage basin
    Mar. 21, 2019
    Wikipedia Santa Ana river
    CC BY-SA 4.0
    This downstream reuse for drinking water is called unplanned potable reuse.refers to situations in which a source of water is mostly previously used, treated, reclaimed municipal wastewater, occurs, for example, when a community gets its water supply from a river that receives water from upstream treated wastewater discharges Examples of this kind of reuse occur in the Santa Ana River in southern California, the Platte River downstream from Denver, the Ohio River near Cincinnati and the Occoquan Watershed southwest of Washington, DC.[2]

    As the world's population grows, unplanned potable reuse and the methods used to purify this water for human consumption will become more important.[2]


    [1] International Water Association. (2022). A brief history of water and health from ancient civilizations to modern times.

    [2] Angelakis, A. N., et al. (May 11, 2018). Water reuse: From ancient to modern times and the future. Frontiers in Environmental Science.

    [3] Getty Conservation Research Foundation Museum. (n. d.). Mesopotamia: Civilization begins.

    Climate Change

    In addition to water, most terrestrial life depends on solar energy. About half of the sunlight reaching our atmosphere strikes the surface, where it is absorbed and radiated as infrared light, also called heat. About 90% of this heat is absorbed by greenhouse gases and reradiated, slowing heat loss into space.[1]

    What is the Paris Agreement and how does it work?
    United Nations
    Sep. 24, 2020
    Embedded video, no copy made
    Global warming is the result of long-term heating of Earth's surface starting in the pre-industrial period, between 1850 and 1900, due to fossil fuel burning, which increased the amount of greenhouse gases in the atmosphere.[6]

    There is ample evidence for human-caused climate change:

    On February 9, 2023, UN Secretary-General António Guterres warned that large cities, including Cairo, Lagos, Maputo, Bangkok, Dhaka, Jakarta, Mumbai, Shanghai, Copenhagen, London, Buenos Aires, Santiago, Los Angeles and New York would be impacted by sea level rise. He said that more than 900 million people living in coastal areas, more than one-in-ten on our planet, would need to relocate, creating increased competition and conflict for clean water, land and other resources.[17]

    The U.N. has determined that:

    Temperature change in the U.S. between 1900 and 2020
    Temperature change in the U.S.
    between 1900 and 2020
    Apr. 1, 2021
    Wikipedia climate change in the United States
    public domain
    In the U.S., climate change will likely result in the following regional changes.


    Northwest: Southeast: Midwest:
    Salton Sea
    Salton Sea
    Mar. 10, 2010
    Wikipedia Salton Sea
    CC BY-SA 4.0

    In 1905 the Colorado River flooded a dry basin, creating California's Salton Sea. It became a haven for tourists and wildlife. By the 1980s, the sea was cut off from its Colorado water supply, sustained by agricultural runoff, full of pesticides and fertilizers.[13]

    The sea's local community consists primarily of Latino agricultural workers and Indigenous Tribe members, now subjected to the smell of rotting fish and lead and chromium toxins. Blowing dust, laced with harmful algae and bacteria, affects more than 650,000 people in surrounding communities.[13]

    Since 2003, the sea's surface area declined by 38 square miles, leaving behind a mass store of briny lithium, an important component of electric vehicle batteries and clean energy storage. Efforts to mine this element may further damage the drying sea.[13]

    Alternatives to restore the sea, including bringing water from the Sea of Cortez and building a desalination plant were suggested but have not yet been implemented.[13]

    The Paris Agreement, a legally binding international treaty, was adopted on December 12, 2015 by 196 parties at COP 21 in Paris. It entered into force on November 4, 2016.[5]

    The agreement marked the first time nations united in a common cause to combat climate change. Its goal is to limit global warming to 1.5Co by reducing greenhouse gases.[5] (Degree changes are noted as Co or Fo while specific temperatures are noted as oC or oF.)

    Greenhouse gas emissions per person
    Greenhouse gas emissions per person
    IPCC AR6 Working Group III
    Feb. 27, 2022
    Wikipedia greenhouse gas emissions
    CC BY-SA 4.0
    The UN Climate Change Conference in Glasgow, COP26, brought together leaders, participants and delegates from 120 countries, and nearly four thousand media representatives.[4]

    The countries agreed to:

    Additional steps included:

    In September 2022, Denmark became the first country to pledge funding for climate-related loss and damage. The country vowed to spend more than $13 million to help developing nations taking the biggest hit from rising global temperatures. The world's most vulnerable countries, like Bangladesh and Haiti need far more, but Denmark's effort is a start.[10]

    Environmental justice advocates and developing world leaders have argued that rich countries bear a greater responsibility for causing climate damage and should pay for economic losses, damaged infrastructure and other climate-related destruction.[10]

    Wealthy countries like the U.S. have oppposed efforts to create a dedicated loss and damage fund, claiming that a financial commitment would imply that rich countries, the primary polluters, are legally liable for climate damage.[10]

    But in November 2022, new pledges made during the United Nations climate conference in Egypt are aimed at directly aiding vulnerable countries. New Zealand committed $12 million to support Pacific Islanders, Belgium $2.6 million to Mozambique, and Austria $52 million over four years for a disaster support initiative.[16] During summer 2022, Jordanians went without water for as long as three weeks. Population growth, decreasing water supplies and climate change, damaged and inefficient infrastructure and geographical challenges have only made things worse. The resulting shortages serve as a warning of what the future might hold for the region's water future.[14]

    Which greenhouse gas is actually the worst?
    Aug. 16, 2018
    Embedded video, no copy made
    All of Jordan's major water sources are near its borders. Water must be transported inland. Due to increased fuel costs, the process is becoming more expensive.[14]

    Rainfall has significantly decreased during the last few decades. Warmer temperatures mean that rain evaporates quickly. Longer and hotter summers have also shortened growing seasons.[14]

    The Jordan River, which used to feed the Dead Sea,Dead Sea and Sea of Galilee in Jordan
    Dead Sea and Sea of Galilee in Jordan
    Aug. 26, 2006
    Wikipedia Dead Sea
    public domain
    is now flowing at less than 10% of its historical average and its tributary, the Yarmouk River has been significantly affected by a water shortage.[14]

    The rivers Jordan shares with Israel and Syria have been diverted by those countries for many years, leading to Jordan's reliance on water extracted from underground aquifers. whic are being drained at twice the rate at which they are naturally replenished. This water is about 60% of the country's water supply.[14]

    Jordan's population is more than 11 million and includes more than 760,000 people registered with the United Nations as refugees, who are particularly affected by the water crisis because they are unable to afford transported water. The average amount of water available each year to a Jordanian resident, about 80 cubic meters, is far below the absolute water scarcity threshold of 500 cubic meters set by the United Nations.[14]

    A large-scale desalination project in the port city of Aqaba on the Red Sea is being planned, but it will be many years before the plant is operational.[14]

    Jordanian farmers were using abut 70% of the country's water supply, but increased efficiency and lower water-use crops have lowered agricultural use to 50%.[14]

    One solution involves buying water from Israel. In November 2022, Jordan and Israel signed a water-for-energy agreement at the United Nations climate conference in Sharm el Sheikh.[14]

    Carbon dioxide equivalent is measured in metrics tons. It is the standard unit of measure for climate change sustainability goals and targets, and a method for converting greenhouse gases based on their global warming potential (GWP)a measure of how much energy the emissions of 1 ton of a gas will absorb over a given period of time, relative to the emissions of 1 ton of carbon dioxide[2]

    This standardization allows for universal measurement. For example, one metric ton of methane has a GWP of 29.8 times that of CO2.[2]

    Greenhouse Gases[2],[3]
    greenhouse gas ↕ formula ↕ CO2 equivalent ↕ information
    carbon dioxide CO2 1
  • most common at 79%
  • used as baseline for collective reporting
  • water vapor H2O 0
  • stays in the air for about 9 days before turning into rain or snow
  • methane CH4 29.8
  • about 25%, stays in atmosphere about 10 years
  • nitrous oxide N2O 273
  • about 7%
  • colorless gas used in rocket fuel and aerosol
  • stays in atmosphere for 114 years
  • ground-level ozone O3 65
  • about 95% comes from human activity
  • originates from burning of oil, gasoline and coal
  • trifluor-
    CHF3 12,400
  • most abundant hydrofluorocarbon
  • atmospheric lifespan of 260 years
  • used in fire suppressants, silicon computer chip engraving
  • hexafluor-
    C2F6 12,200
  • refrigerant and used in semiconductor manufacturing
  • stays in the atmosphere for as long as 10,000 years
  • sulfur hexafluoride SF6 25,200
  • most potent greenhouse gas
  • stays in atmosphere for 3,200 years
  • used as an insulator in electric power systems, dispersal of chemical agents
  • trichloro-
    CCl3F 4,600
  • used as a coolant in refrigerators and foam in liquid fire extinguishers
  • produces chlorine molecules depleting ozone layer
  • perfluoro-
    C12F27N 7,100
  • about 0.2 parts per trillion
  • can stay in atmosphere for over 500 years
  • sulfuryl fluoride SO2F2 4,780
  • used to manage termites
  • only identified as a greenhouse gas in 2009
  • has an atmospheric lifetime of up to 40 years
  • concentration of 1.5 parts per trillion, increasing by 5% per year
  • Climate change obstructionists use several methods to counter climate change protection and action:

    Climate change skeptics utilize easily refuted arguments: The Yale Program on Climate Change identified six distinct groups, Six Americas, based on their beliefs, attitudes, policy support, and behavior about climate change:
    What is the most abundant element in Earth`s crust?
    Rare has identified eight principles for effective climate change communication: Climate change researchers have a new tool to identify greenhouse gases. Backed by former vice president Al Gore and other big environmental donors, Climate TRACE can track emissions down to individual power plants, oil fields and cargo ships. Those estimates are part a new global list of emitters released in November 2022.[15]

    Climate TRACE is a nonprofit coalition of environmental groups, technology companies and scientists. The project uses software to collect and analyze satellite and other data project emissions for countries, industries and individual polluting facilities. It catalogs more than 72,000 steel and cement factories, power plants, oil and gas fields, cargo ships and cattle feedlots. Climate TRACE is working with regional governments in Mexico, Brazil, South Africa, Spain and Italy to provide information about local emissions.[15]


    Senator throws snowball in Senate
    Feb. 27, 2015
    Embedded video, no copy made
    [1] NASA. (Aug. 15, 2022).
    The causes of climate change.

    [2] Sustain Life. (Apr. 18, 2022). 10 harmful greenhouse gases other than CO2.

    [3] Environmental Protection Agency. (May 16, 2022). Overview of greenhouse gases.

    [4] United Nations. (n. d.). Together for our planet.

    [5] United Nations. (n. d.). The Paris Agreement. Climate Change.

    [6] NASA. (Sep. 1, 2022). Global warming vs. climate change. Global Climate Change.

    Annual CO<sub />2</sub> emissions by country
    Annual CO2 emissions by country
    M. Roser
    Mar. 5, 2022
    Wikipedia greenhouse gas emissions
    CC BY-SA 3.0
    [7] NASA. (Sep. 1, 2022). How do we know climate change is real? Global Climate Change.

    [8] Rainforest Alliance. (2012). 6 claims made by climate change skeptics-and how to respond.

    [9] Brulle, R. J. (n. d.). A sociological view of the effort to obstruct action on climate change. American Sociological Asssociation, 49(3).

    [10] Winters, J. (Sep. 22, 2022). Denmark leads the way on 'loss and damage.' Grist.

    [11] NASA. (Sep. 28, 2022). The effects of climate change.

    [12] Leiserowitz, A., et al. (Jan. 12, 2022). Global warming's six Americas, September 2021. Yale Program on Climate Change.

    [13] Teirstein, Z. (Oct. 13, 2022). Can the Salton Sea be saved? Grist and High Country News.

    How much water needed to make a ton of steel?
    [14] Zraick, K. (Nov. 9, 2022). Jordan is running out of water, a grim glimpse of the future. The New York Times.

    [15] Zhong, R. (Nov. 9, 2022). Who's driving climate change? New data catalogs 72,000 polluters and counting. The New York Times.

    What element is found in all known life?
    [16] Winters, J. (Nov. 15, 2022). Rich countries pledge 'loss and damage' funding. Grist.

    [17] Berwyn, B. (Feb. 14, 2023). Sea level rise could drive 1 in 10 people from their homes, with dangerous implications for international peace, UN secretary general warns. Inside Climate News.

    Which moon of Saturn has water geysers?
    [18] United Nations. (n. d.). Water and climate change.

    [19] Rakhimov, R., et al. (n. d.). Eight principles for effective and inviting climate communication.

    Water Quality

    World's water
    World's water
    H. Perlman, USGS
    All of Earth's Water in a Single Sphere
    public domain
    We take for granted that when we turn the faucet handle that clean, clear and drinkable water will be instantly available and unlimited. But many places on Earth, that's not the case. According to the United Nations: Water qualitythe chemical, physical and biological characteristics of water based on usage standards varies greatly across our globe.

    UNESCO's 2022 Water Development Report emphasized the importance of caring for Earth's groundwater, which accounts for about 99% of all liquid freshwater on Earth. Nearly 50% of the world's urban population depends on underground water sources.[5]

    Gross domestic product (GDP)total monetary value of all finished goods and services produced in a country per capita and urbanizationconcentration of human populations into towns and cities as a percent of land area for countries with the best water versus those with the worst differ significantly.[2] The average GDP for the best 10 is more than 29 times that of the worst 10, and the average urbanization for the best 10 is nearly three times that of the worst 10.

    The major issues affecting water are pollution, inequitable distribution, regulation and climate change.[5]

    Arab region:

    10 Countries with the Best Drinking Water[1],[2]  
    country↕ EPIenvironmental performance index, uses 40 performance indicators in 11 issue categories to rank countries on climate change performance, environmental health and ecosystem vitality score↕ GDP per capita
    in U.S. $↕
    % of land area↕
    Finland 100.0 48,419 88.12
    Iceland 100.0 48,606 93.90
    Netherlands 100.0 49,787 92.24
    Norway 100.0 65,389 82.97
    Switzerland 100.0 59,317 73.92
    United Kingdom 100.0 40,502 83.90
    Malta 99.8 38,388 94.74
    Germany 99.0 45,936 77.45
    Luxembourg 98.6 96,793 91.45
    Sweden 98.5 47,718 87.98
    Average   54,086 86.67
    Asia and the Pacific: Australia:
    10 Countries with the Worst Drinking Water[1],[2]
    country↕ EPI score↕ GDP per capita
    in U.S. $↕
    % of land area↕
    Lesotho 7.2 2,280 29.03
    Guinea-Bissau 6.7 1,596 44.20
    Eritria 6.3 2,176 41.35
    Madagascar 5.9 1,678 38.53
    Burundi 5.3 660 13.71
    Togo 5.1 1,574 7.89
    Nigeria 4.9 5,315 51.96
    Niger 1.4 944 16.63
    Central African
    0.0 763 42.20
    Chad 0.0 1,746 23.52
    Average   1,873 30.90
    Europe: Latin America and the Caribbean:
    Our drinking water - Is the world drying up?
    DW Documentary
    Mar. 20, 2022
    Embedded video, no copy made
    South America: Sub-Saharan Africa: U.S.:
    What does WOTUS mean?
    UNESCO's International Initiative on Water Quality (IIWQ) Agenda and Sustainable Development Goals (SDG) 6 Clean Water and Sanitation includes targets and goals for world-wide water improvement:
    What is the most common greenhouse gas?
    The idea of World Water Day was introduced in 1992 during the United Nations Conference on Environment and Development in Rio de Janeiro. The UN General Assembly declared March 22 as World Day for Water and the observation of the event that began in 1993. It aims to raise awareness about water conservation and support for the United Nations' Sustainable Development Goal 6, describing steps needed to ensure safe water and sanitation for the world by 2030.[6]

    The 1972 Clean Water Act, 1974 Safe Drinking Water Act, 1986 Safe Drinking Water Act Amendments and 1996 Safe Drinking Water Act Amendments are supposed to guarantee that all U.S. inhabitants have access to clean and safe water. For nearly a decade Flint, Michigan residents consumed drinking water that failed to meet federal regulations.[23]

    Flint River, Michigan
    Flint River, Michigan
    Army Corps of Engineers
    Wikipedia Flint River (Michigan)
    public domain
    On April 25, 2014 Flint changed its municipal water supply source from the Detroit-supplied Lake Huron water to the Flint River. The switch caused pipe corrosion which leached lead and other contaminants exceeding EPA standards into the city drinking water system.[24] In October 1, 2015 Flint residents were advised not to drink their tap water unless it had been filtered through a lead-removal filtration system and the city reconnected the original Detroit water system. On January 10, 2016 the Michigan Department of Health declared a state of emergency.[25]

    The damage was already done:

    To settle myriad lawsuits, Michigan will pay $600 million, Flint will pay $20 million, the McLaren Regional Medical Center will pay $1.5 million.[23]

    PFAS and other toxins build up in the food chain
    PFAS and other toxins build up in the food chain
    O. Paulsen
    May 25, 2018
    Wikipedia per- and polyfluoroalkyl substances
    CC BY-SA 3.0
    PFASa group of man-made chemicals that includes PFOA, PFOS, GenX, and many other chemicals are contaminants of emerging concern (CEC)unregulated substances often found in pharmaceutical and personal care products that end up in sewers and that cannot be totally removed by usual wastewater treatment processes Researchers at USC's Keck School of Medicine found that PFAS exposure alters biological processes, including amino acida simple organic compound containing both a carboxyl (-COOH) and an amino (-NH2) group formation and fat metabolismchemical processes in a living organism that keep it alive in children and young adults. This disruption is related to increases in developmental disorders, heart and metabolic diseases and cancer.[15]

    PFAS are synthetic chemicals widely used in food packaging, firefighting foams and non-stick pan, paper, and textile coatings because they are oil, water and stain resistant.[19]

    PFAS samples were collected in North America, Europe and the Arctic. They have been found in the Pacific Ocean, the Great Lakes, Baltic Sea and Mediterranean Sea.[18]

    PFAS were first identified in the tissues of fish, birds, marine mammals, and specifically bald eagles, polar bears, albatrosses and seals in the early 2000s. Fish-eating predatory animals were found to contain concentrations greater than could be accounted for in their diets.[18]

    The Centers for Disease Control and Prevention National Health and Nutrition Examination Survey (NHANES) measures blood PFAS in the U.S. population every two years, starting in 1999-2000, estimating that PFAS-related chemicals are in the blood of 97% of the U.S. population.[19]

    Since 2002, U.S. production and use of PFOS and PFOA in the United States have declined. From 1999-2000 to 2017-2018, blood PFOS levels declined by more than 85% and from 1999-2000 to 2017-2018, blood PFOA levels declined by more than 70%. As PFOS and PFOA are phased out humans may be exposed to other PFAS.[20]

    In February 2023, the EPA announced that $2 billion in grants from the Bipartisan Infrastructure Law was available to communities to address PFAS issues in drinking water.[13]

    On March 14, 2023, the EPA announced the proposed National Primary Drinking Water Regulation (NPDWR) for six PFAS including perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA), hexafluoropropylene oxide dimer acid (HFPO-DA), perfluorohexane sulfonic acid (PFHxS), and perfluorobutane sulfonic acid (PFBS).[21]

    The proposed PFAS NPDWR should be finalized by the end of 2023. If implemented, the EPA expects the new rules will prevent thousands of deaths and reduce tens of thousands of serious PFAS-related illnesses.[21]

    By May 2023 10 states had banned food containers containing PFAS along with hundreds of cities.[27]

    In May 2023 Sen. Cynthia Lummis (R. Wy.) introduced the Water Systems PFAS Liability Act. If passed, the act would hold polluters responsible for cleaning up PFAS discharges under the 1980 Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The new law would close a loophole in the 1980 law that would prevent polluters from passing on cleanup costs to water system customers.[26]

    EPA proposes bold new limits for PFAS in drinking water
    Environmental Working Group
    Mar. 14, 2023
    Embedded video, no copy made
    EPA proposed National Primary Drinking Water Regulation (NPDWR)[21]
    compound↕ MCLGthe maximum level of a contaminant in drinking water at which no known or anticipated adverse effect on the health of persons would occur proposed MCLthe maximum concentration of a chemical that is allowed in public drinking water systems proposed
    PFOA 0 4.0 ppt
    PFOS 0 4.0 ppt
    PFNA 1.0 1.0
    PFHxS 1.0 1.0
    PFBS 1.0 1.0
    HFPO-DA 1.0 1.0
    One approach to PFAS removal uses colloidal activated carbon (CAC)a material used to block PFAS from entering groundwater called PlumeStop, which acts like a filter in underground aquifers. PlumeStop is created from coconuts ground into small particles inserted into a liquid that slips into rock pores, creating a permeable reactive barrier (PRB)an inground wall which removes impurities from water that passes through it between PFAS and water sources.[14]

    Which moon of Jupiter may have an ocean?
    AVANTech, a wastewater treatment company, recently developed a PFAS capturing and solidification system that uses modified ion exchange.[16] The process uses a specialty absorbent that attracts PFAS from water, concentrating the PFAS onto a solid that is easily disposed.[17]


    [1] World Population Review. (2023). Water quality by country 2023.

    [2] Yale Center for Environmental Law & Policy. (n. d.). Sanitation & drinking water. Environmental Performance Index.

    What country first pledged funding for climate-related loss and damage?
    [3] United Nations. (n. d.). Goal 6: Ensure access to water and sanitation for all.

    [4] United Nations. (n. d.). Global issues: Water.

    [5] UNESCO. (2022). The United Nations world water development report 2022: Groundwater: Making the invisible visible.

    [6] (Mar. 22, 2023). World water day 2023: Innovative ways for sustainable water management.

    [7] OECD. (n. d.). OECD - EC DG environment initiative on the economic aspects of implementing the EU water framework and floods directives.

    [8] OECD. (Nov. 22, 2018). Managing the water-energy-land-food nexus in Korea.

    [9] OECD. (Aug. 1, 2013). Making water reform happen in Mexico.

    On what continent are most countries with the worst drinking water located?

    [10] OECD. (Nov. 27, 2017). Water Charges in Brazil.

    [11] Australian Government Department of Climate Change, Energy, the Environment and Water. (Dec. 9, 2022). National water policy.

    [12] Australian Government Department of Climate Change, Energy, the Environment and Water. (Dec. 9, 2022). National water initiative.
    [13] Water Online. (Feb. 13, 2023). Biden-Harris administration announces $2B in bipartisan infrastructure law funding to states and territories to address emerging contaminants like PFAS in drinking water.

    [14] Moore, R. (Mar. 9, 2023). New study confirms a more sustainable approach to treat PFAS. Water Online.

    What is the source of Earth`s water?
    [15] Hamashige, H. (Feb. 21, 2023). Keck School of Medicine study finds "forever chemicals" disrupt key biological processes. Keck School of Medicine, USC.

    [16] AVANTech. (Apr. 26, 2022). Per- and polyfluoroalkyl substances (PFAS) treatment and removal.

    [17] Reed, M. (Mar. 7, 2023). Description of PFAS removal process. Personal correspondence.

    [18] Giesy, J. P. & Kannan, K. (Mar. 1, 2001). Global distribution of perfluorooctane sulfonate in wildlife. Environmental Science & Technology, 35(7), 1339-1342.

    What three areas did Executive Order 13990 address?
    [19] Lewis, R. C., Johns, L. E., & Meeker, J. D. (May 19, 2015). Serum biomarkers of exposure to perfluoroalkyl substances in relation to serum testosterone and measures of thyroid function among adults and adolescents from NHANES 2011-2012. International Journal of Environmental Research and Public Health, 12(6), 6098-6114.

    [20] Agency for Toxic Substances and Disease Registry. (Dec. 22, 2022). PFAS in the U.S. population.

    [21] Environmental Protection Agency. (Mar. 23, 2023). Per- and polyfluoroalkyl substances (PFAS) proposed PFAS national primary drinking water regulation.

    [22] American Water Works Association. (2022). State of the water industry '22 executive summary.

    What mineral found on Mars indicates that planet may have had water?
    [23] Chawaga, P. (Mar. 28, 2023). Judge orders Michigan to pay $600 million to victims of Flint water contamination. Water Online.

    [24] Centers for Disease Control and Prevention. (May 28, 2020). Flint water crisis. Community Assessment for Public Health Emergency Response (CASPER).

    [25] Centers for Disease Control and Prevention. (Jul. 2016). Community assessment for public health emergency response (CASPER) after the Flint water crisis: May 17-19, 2016.

    [26] Association of Metropolitan Water Agencies. (n. d.). AMWA welcomes introduction of the 'Water Systems PFAS Liability Protection Act.','polluter%20pays'%20legislation.%E2%80%9D

    [27] Winters, J. (May 8, 2023). Oregon bans plastic foam and PFAS in food containers, promotes reusable alternatives. Grist.


    What ancient civilization developed advanced sewage systems?
    In 1973, EPA published regulations defining navigable waters to include traditional navigable waters, tributaries of traditional navigable waters, interstate waters and intrastate lakes, rivers, and streams used in interstate commerce. Collectively these bodies of water are known as Waters of the United States (WOTUS).[1]

    In 1986 federal regulations expanded WOTUS to include

    What are Earth`s five spheres?
    Excluded are waste treatment systems, treatment ponds or lagoonsshallow body of water separated from a larger body of water by a reef, barrier island, barrier peninsula or isthmus designed to meet the requirements of Clean Water Act.[1]

    For the next three decades several state, appellate court and Supreme Court cases reinterpreted the 1986 definition. The 2015 Clean Water Rule excluded ephemeral streamsa temporary stream that flows as the result of precipitation[1] from WOTUS.

    On January 20, 2021, President Biden signed Executive Order 13990 on Protecting Public Health and the Environment and Restoring Science to Tackle the Climate Crisis. The order required federal agencies to review existing regulations to ensure that they addressed science, climate change and social justice.[1]

    What are the major issues affecting water?
    On January 18, 2023 per that order, the Department of the Army, Corps of Engineers, Department of Defense and the EPA instituted a new rule to expand WOTUS removing limitations to WOTUS that had been instituted by the prior administration. The revised rule recognizes the rights and responsibilities of states to prevent and reduce pollution and to enhance and restore land and water resources.[1]

    Clean Water Act programs will need to ensure their waters are protected by federal law. Where they do not Tribes and states have authority.[1]

    How a beaver boom is reshaping floods and fire
    Jun. 8, 2022
    Embedded video, no copy made
    Twenty-four Republican-lead states have sued the EPA over these new requirements. They believe that the new rule is too liberal in its protection of the nation's waters.[2]

    In April 2023 the EPA announced $41 million in assistance under the America's Infrastructure Act to help solve wastewater challenges. The funding will help rural, underserved and Tribal communities to assess water needs, identify solutions and access funding from the Infrastructure Investment and Jobs Act.[3]

    The act has five priorities: financing and funding, protection of water quality, improvement of Tribal wastewater systems, assistance to communities with decentralized water systems and lagoon wastewater treatment.[3]


    [1] Federal Register. (Jan. 18, 2023). Revised definition of "Waters of the United States."

    [2] Chawaga, P. (Mar. 1, 2023). Two dozen states challenge U.S. EPA's new WOTUS rule. Water Online.

    [3] Environmental Protection Agency. (Apr. 27, 2023). EPA invests $41 M in new technical assistance to help communities address wastewater challenges.


    Attenborough, D. (n. d.). How to save our planet. Our Planet.

    Attenborough, D. (Apr. 17, 2020). Our planet. One Planet.

    Bohr, J. (Apr. 17, 2020). The structure and culture of climate change denial. Footnotes, 49(3). American Sociological Association.

    How Earth would look if all the ice melted
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    Brixi, H., Sara, J. J., & Peschka, M. P. (Nov. 13, 2022). People and planet together: Why women and girls are at the heart of climate action. World Bank Blogs.

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    CNN. (Aug. 16, 2022). Think it's hot now? New report shows it's only going to get hotter.

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    Environmental Protection Agency. (Sep. 28, 2022). Regulations and end-use specifications explorer (REUSExplorer).

    On what continent are most countries with the best drinking water located?
    Garner, A. J., et al. (Jan. 23, 2023). Evaluating knowledge gaps in sea-level rise assessments from the United States. Earth's Future, 11(2).

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    Goodall, L. (Feb. 23, 2019). Climate change scientists look to Maori and other indigenous people for answers. Stuff.

    IPCC. (n. d.). Sixth assessment report. Working Group 1: The Physical Science Basis.

    During which extinction event did the Chicxulub crater form?
    Kaplan, S. (Nov. 3, 2021). The world will burn through its 'carbon budget' in 11 years without big emissions cuts, scientists say. Washington Post.

    Mechler, R., Bouwer, L. M., Schinko, T., Surminski, S. & Linnerooth-Bayer, J. (eds.). Loss and damage from climate change: Concepts, methods and policy options. (2019). SpringerLink open access. (2022). The Köppen climate classification system.

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    Trees across the U.S. face dire threats, new report shows
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    National Research Council. (2012). Lines of evidence: Solar influences.

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    What were the 6 groups identified by the Yale Climate Change program?
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    Winters, J. (May 11, 2023). More than 150 countries agree to ban 3 toxic chemicals. Grist.

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    Yoder, K. (Apr. 21, 2023). A common talking point about climate change gets it all wrong, new study says. Grist.

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