Settled Science

C. Hochman and O. TangSeptember 25, 2016Climate ChangeFeatures

2014 was the hottest year on record globally.

Even more surprisingly, 2014 was a record year for climate and general environmental policy. In June, the Environmental Protection Agency (EPA) proposed the Clean Power Plan, the first-ever governmental regulation of carbon emissions. In November, the United States and China adopted a set of guidelines to reduce the amount of greenhouse gases produced by the world’s two largest economies.

In his 2015 State of the Union address, President Barack Obama named climate change the “greatest threat to future generations.” However, in early 2015, conservative political commentator and radio talk show host Rush Limbaugh dismissed the entire body of research behind climate change as “one of the greatest hoaxes in science.” He went on to claim that all evidence for the anthropogenic origins of global warming is fabricated.

“You’re gonna learn how to fake ice core sample temps. You’re gonna learn how to go to obscure places in Siberia and dig 30 feet down and find an age-old tree trunk that’s been buried that has tens of thousands of years of temperature data in the bark. You’re gonna come up with hockey stick theories left and right.”

Even though nearly all climate scientists agree that human activity has caused global warming, environmental policy has long been treated as a political football. Many political commentators have even claimed that the global climate has not undergone significant shifts since 1950, despite measurable evidence. Temperatures from 2001 to 2012 were warmer than any previous decade in every region of the United States.

Today, however, the argument science-skeptical politicians have lodged against climate change has shifted from outright denial to claiming that climatic shifts happen independent of human action, therefore absolving humanity of any blame. This belies an extreme lack of understanding of basic climate change science. In 2014, the Intergovernmental Panel for Climate Change, a UN-affiliated board of climate scientists, published the latest Compilation of Biennial National Reports saying that the “scientific evidence for warming of the climate system is unequivocal.”

What’s also undisputed is the root cause of our changing climate — greenhouse gases. This class of gases includes carbon dioxide, water vapor, methane, nitrous oxide, ozone, and halocarbons. Though certain halocarbons can cause up to 23,500 times the damage as carbon dioxide, carbon dioxide is widely considered to have the greatest overall impact on the climate, as over 80% of greenhouse gases is carbon dioxide.

In balanced doses, carbon dioxide and other greenhouse gases work with the sun and the earth to maintain a constant temperature suitable for plant and animal life. The sun’s rays continuously flow energy to earth, providing us with light and heat. When the sun’s energy is not used by plants or humans, the earth absorbs it and radiates it back towards the atmosphere in the form of infrared radiation.Think of greenhouse gases as a blanket that absorbs some of this heat energy and traps it within the planet. This is not necessary a negative thing: these gases keep the Earth’s average temperature at about 15°C: warm enough to sustain life for humans, plants and animals. Without these gases, the Earth’s average temperature would be about -18°C, too cold for most life forms. This phenomenon is known as the greenhouse effect.

Problems arise when the amount of greenhouse gases dramatically increase without a proportional decrease in the energy emitted the sun or reflected by the Earth, like being wrapped in a thick, woolen blanket in the middle of summer. The higher the level of greenhouse gases, the more heat energy from the sun is trapped close to the earth and the hotter the climate becomes.

The basis of many arguments against human-induced climate change is that the amount of greenhouse gases in the environment naturally changes, so the current jump in atmospheric carbon dioxide is only part of a millennia-long trend. However, there is an abundance of evidence that modern human activity has caused increased carbon dioxide in the atmosphere, the leading cause of climate change. Burning of fossil fuels — whether by cars for transportation, power plants for electricity, or factories for industry — is the main cause of increased carbon emissions and therefore evidence of anthropogenic climate change.

Over the last century, as human emissions of carbon dioxide increase, so too does the atmospheric concentration of carbon dioxide. This, as previously discussed, has led to an increase in global temperatures. Raw climate data does not prove in of itself that humans have caused climate change. Many have said that carbon dioxide levels have fluctuated throughout time. This is only partially correct — between 400,000 years ago and 1950, atmospheric carbon dioxide levels remained approximately constant, around 180 to 300 parts per million.

Today, according to the National Oceanic & Atmospheric Administration, carbon emissions have jumped higher than that range for the first time in almost half a million years. (See an animation from NOAA here.) 1950 marked the first time in over 400,000 years of measurable data that global carbon dioxide levels began to rise above 300 parts per million, an upward trend that does not appear to be ending anytime in the near future.

Not only do many believe that these immense jumps in carbon concentration are natural, many also think that the current rise of human-produced carbon dioxide levels is a mere fraction of carbon dioxide released naturally, therefore clearing humans of blame. This also is simply not true. If the amount of carbon dioxide did increase naturally, there would be a corresponding decrease in oceanic carbon levels.

When ocean water is exposed to the atmosphere, carbon dioxide and other gases dissolve into the ocean — imagine tiny gas bubbles diffusing into the ocean. There, carbon dioxide bonds with water to form an acid. An easy way to measure the carbon concentration in ocean water is to measure the acidity using the pH scale. Instead of becoming less acidic, ocean water is increasing in acidity, leading to substantial declines in fish and shellfish populations.

Again, this shows that nature is actually absorbing more carbon dioxide than it is producing. Far from absolving humanity of responsibility for climate change, measurements show that nature is trying to accommodate the negative impacts of the increase in human-generated carbon dioxide emissions.

Scientists can see the amount of carbon dioxide in the air from fossil fuels by looking at the different isotopes of carbon (carbon atoms with different numbers of neutrons). Carbon comes in three isotopes, but all can combine with other elements to form molecules like carbon dioxide. The only difference in each isotope’s physical properties is the weight – carbon-12 is the lightest, and carbon-14 is the heaviest.

Plants, which eventually turn into fossil fuels, use carbon, but they do not use each isotope equally. It’s easier for plants to use the lightest, carbon-12. However, the weight of the carbon has no impact on carbon dioxide produced by other processes (like when we exhale). This makes the composition of carbon dioxide made from burning fossil fuels different from typical carbon dioxide produced as a natural by-product. When more fossil fuels are burned, the amount of light carbon in the atmosphere, carbon-12, increases.

Trees use this proportionally-lighter atmospheric carbon to build cellulose, the woody parts of a plant. Each ring of a tree’s trunk can be dated by looking at how fast the tree grows, so the amount of carbon-12 can be found at a certain point in time by looking at a certain ring. Tree-rings dating back to the beginning of the Industrial Revolution in 1850 show a dramatic increase in the amount of carbon-12. This means that there is a correlation between the first widespread consumption of fossil fuels and an increase in the amount of carbon dioxide in the environment. In the last 150 years, the amount of carbon-12 in the atmosphere has skyrocketed, meaning that more and more fossil fuels are combusted.

Increasing amounts of atmospheric carbon dioxide have led to a 0.16°C per decade warming trend since 1979. While this may not sound like much, the effects of each decade’s increase compounds over time. Since the 1880, global temperatures have risen almost 1.5°C. Climate scientists have termed the graph of rising temperatures “the hockey stick” for its exponential upward growth. Climate change impacts weather patterns, leading to deadlier and deadlier catastrophes. A USA Today investigation found that in 2012 alone, natural disasters cost the world economy a total of over 200 billion dollars.

Higher temperatures also mean a decrease in glacial ice and snow. The increase in ocean levels, resulting from the melted ice, will displace millions –mostly in low-income, low-lying island countries. Kiribati, a Pacific Ocean island nation with an average national income around $1,500 a year, will be among those impacted the most. Tuvalu, a neighboring island, will probably disappear within the next century. The San Blas archipelago, where the indigenous Kuna people of Panama have traditionally lived, will be underwater in the next 20 to 30 years. While the majority of emissions are produced by industrialized nations, citizens in these nations will not be the ones most affected by global warming.

This means that it is easy for people living in the United States, people like Rush Limbaugh, to sit and myopically deny the dangers of climate change. For wealthy citizens of wealthy countries, it’s really no danger. For them, the most direct repercussions of ignoring climate change is that their children will no longer be able to see polar bears. However, for politicians, the drawbacks of addressing one of the greatest threats to humankind of the modern era are multifarious. Fixing climate change will require much government spending. And it will be difficult to justify that spending to a constituency, especially one that denies the very existence of the problem.

However, this represents the lowest variety of political pandering to anti-science beliefs coursing throughout American society. It is the job of scientists, media figures, and politicians to educate the populace about indisputable issues that need to be addressed, rather than sweeping reform off the table and doing what is politically popular.

The science around global warming is settled. It is time for the politicians of the world to catch up.

When American politicians fail to act, it is the rest of the world that bears the brunt of climate change. An oft-repeated quote is: “When the U.S. sneezes, the rest of the world catches a cold.” Nowhere is this more true than in the case of climate change. In 2008, America was one of the top carbon dioxide emitting countries, yet it was one of only a few countries that have not signed the Kyoto Protocol, the landmark UN environmental treaty signifying a commitment to reduce greenhouse gases.

There is a disconnect between countries that benefit economically from producing greenhouse gases and countries dealt the environmental repercussions of a warming world. The 75 high-income countries, as designated by the World Bank, emit half of the world’s carbon dioxide. In contrast, the 50 least-developed nations produce 0.64% of total global emissions. These 50 nations, which are primarily in sub-saharan Africa, are suffering from severe droughts caused by global warming. Droughts that threaten to destabilize their agricultural economies.

Yet this divide between upper and lower income countries can be bridged. There are many innovations created by climate scientists to mitigate the effects of global warming. Technology is an important tool for reducing the vulnerability of climate change disasters around the world, and for formulating a resilient response.

One recent, promising, invention is called Solar Roadways. Invented in 2006, the basic concept is a road built completely of solar panels that would be used nationwide to create energy. Scott and Julie Brusaw, the parents of this fine brainchild, claim that if all 50 U.S. states used ~3741 billion kilowatt-hours of electricity in 2009. “It’s easy to see that the Solar Roadways could produce over three times the electricity that we currently use in the United States.”

In addition to generating clean energy, with time, these panels will pay for themselves. They can withstand a great amount of weight, and (the inventors should get extra style points for this one), in their model they included LED (Light Emitting Diodes that produce different colored light) lights to “make road lines and signage.”

Pretty cool, huh? This highly-acclaimed project has gotten donations from 165 countries worldwide, in addition to winning many awards and grants. It has also “received two phases of funding from the U.S. Federal Highway Administration for research and development.” The company is working on phase two, a parking lot made of solar panels, currently.

However, not everyone is sold on this idea. The central argument, made by critics including several engineers and multiple angry bloggers, is that solar roadways are impractical. Specifically, that the cost of Solar Roadways would be immense and that repairing the damage to all the solar panels over time would amount to a huge cost. LEDs are expensive, labor would be much more intensive than for normal asphalt roads, and they also argue that LEDs are fragile.

Although some of these arguments, such as the cost, have hit home with the inventors, the fragility argument has been contested. The inventors say that the panels can withstand 250,000 pounds and last for 20 years. The idea of solar roadways is being improved on every day, and although it may have flaws, the world awaits anxiously to see what the inventors can do — or if the roadways will crash and burn like the critics claim they will.

In addition to the problem of clean energy, another growing problem is the lack of a consistent, fresh water supply. According to a 2012 report from the Natural Resources Defense Council, “Lack of safe water and adequate sanitation is the world’s single largest cause of illness.”

There is enough water on Earth to support its growing population if we use salt water. There is only one effective way to do that: desalination. For several years, people have been saying the future of consistent water supply is desalination. But how? Common distillation? Too pricey. Reverse osmosis? Too time consuming. Electrodialysis? Wait, huh? What’s that?

Electrodialysis is a method which desalinates water effectively, while avoiding all the issues of reverse osmosis and distillation. Although effective, it still does not address the serious problem of bacteria. That is where shock electrodialysis comes in. Shock electrodialysis is a type of desalination adds the benefit of eliminating bacteria, while also adding salt. The inventors, a team of scientists working at MIT, still have to work out the kinks, but it seems as if this new invention could be the best method of desalination yet.

Another issue the world is facing due to climate change is the rising water levels. One potential solution to this is the amphibious house. It was thought up by the Dutch, whose country is now a flood zone. A third of the Netherlands lies below sea level, which has, for obvious reasons, been causing problems. Dutch scientists have invented amphibious houses to help solve this.

Amphibious houses are houses that adapt to the water in the area. If water levels are normal, houses remain solidly on the ground; but when the water levels increase, the houses rise on metal poles that have been placed in the ground. In 2005, a series of amphibious houses were built on the river Meuse, so that when there was major flooding in 2011, none of the houses were damaged. The concept of these “swimming houses” is to work with the flooding, rather than against it.

Maybe our Earth is not totally doomed. With inventions like these, our future looks a little better each day.


Brusaw, Scott and Julie. “Phase II Prototype.” Solar Roadways. March 31, 2014.

“CO2 Emissions.” 2015. The World Bank.

Davenport, Coral. “Rising Seas.” March 28, 2014. New York Times.

“Global Climate Change: Evidence and Causes.” Down to Earth Climate Change: Teaching Tomorrow’s Leader’s Today.

“Global Greenhouse Gas Emissions Data.” United States Environmental Protection Agency.

Jacobson, Rebecca. “President calls climate change the ‘greatest threat to future generations’ in State of the Union.” PBS Newshour. January 21, 2015.

Kennedy, Caitlyn. “Does “global warming” mean it’s warming everywhere?” May 6, 2014.

Limbaugh, Rush. “Cruz Demolishes Climate Change Alarmists.” The Rush Limbaugh Show. March 26, 2015.

National Resources Defense Council. “Global Safe Water: Solving the World’s Most Pressing Environmental Health Problem.” March 2, 2012.

“The Greenhouse Effect.” BBC Weather Centre.

“What Is The Greenhouse Effect?” 2015. American Climate Science Toolkit.

Caroline Hochman is 14 years old and lives in New York City. Her favorite subject is history, and her hobbies include playing violin and playing baseball. Opal Tang is 17 years old and lives in Alexandria, Virginia.