200 years of climate science and policy

The good, the bad,
and the ugly

Navigating 200 years of climate
science and policy

The Spanish philosopher George Santayana wrote, “those who cannot remember the past are condemned to repeat it.” When it comes to climate change, repeating the past is a luxury we can’t afford. If partisan politics continues to derail policy or if denial continues to win over science, it will mean irreversible changes to our planet. Future generations will look at ours as the one that didn’t have the courage to act, rather than the one that recognized the fierce urgency of the moment and met it head on.

With this in mind, we’ve created a climate change timeline highlighting the evolution of science, the intrusion of denial, and the sluggishness of policy over the past 200 years. Let’s learn from the mistakes of the past, so we can make tomorrow a brighter—but not hotter—future.

1760
year in analysis
atmospheric co2 levels
280.000(ppm)
global land-ocean temp
-0.08(°c)

This graph illustrates change in global temperature relative to 1951-1980 average temperatures.

Observable changes in the Earth

since the industrial revolution

While politicians have been busy debating the merits of climate science, the physical symptoms of climate change have become increasingly apparent: since the industrial revolution, sea level has grown by 0.9 inches, the atmospheric concentration of carbon dioxide has risen to unprecedented levels, average global temperatures have increased by about 1.0 degree Celsius and, to top it off, the global population has jumped by nearly 600 percent; 15 of the 16 hottest years on record occurred in the 21st century, and 2016 is likely to be the warmest year ever recorded. The graphs included in this timeline serve to show how the Earth has changed over the past 200 years.

Atmospheric Co2 Levels

Global Land-Ocean Temp

(This graph illustrates change in global temperature relative to 1951-1980 average temperatures.)

Sea Level

Global Population

Sources for Graphs:
Atmospheric CO2 levels:

Nasa: Ice-Core data adjusted for global mean; NOAA ESRL DATA: monthly mean CO2.

Global Land Ocean Temp Index:

NASA's Goddard Institute for Space Studies (GISS). Credit: NASA/GISS

Sea Level Rise:

CSIRO, 2015; NOAA, 2015

Global Population:

United Nations Population Division

1760 - 1820

Burn, baby, burn: The industrial revolution spurs unprecedented levels of agricultural and industrial production, initiating the relentless release of carbon dioxide into the atmosphere.

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According to data from the National Oceanic and Atmospheric Administration, in the 650,000 years leading up the industrial revolution, carbon dioxide levels remained below 280 parts per million (ppm). As fossil fuel consumption increased, the atmospheric concentration of carbon dioxide grew, surpassing the 400 ppm mark for the first time in recorded history in 2013.
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1820: Atmospheric CO2 levels at 280 PPM

Science

1824

French mathematician Jean Baptist Joseph Fourier publishes a paper outlining what will later be known as the greenhouse effect.

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Fourier theorized that if our planet was warmed solely by the effects of incoming solar radiation, then it should be much cooler on Earth than it actually is. This led him to conclude that the Earth’s atmosphere acts as a sort of insulation, keeping us nice and toasty. For this discovery, Fourier is credited as the father of the greenhouse effect, although he never used this term himself.
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Science

1859

British scientist John Tyndall discovers that some gases block infrared radiation, concluding that slight changes in atmospheric composition can significantly alter the Earth’s surface temperature.

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Importantly, while Tyndall thought that changing the composition of the atmosphere could alter Earth’s climate, he didn’t believe that manmade emissions would be large enough to have an impact on atmospheric composition.
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Science

1896

Using pencil and paper calculations (because the calculator hadn’t been invented yet) Swedish chemist Svante Arrhenius derived that a doubling in atmospheric carbon dioxide would produce a warming effect between 2.5 and 4.0 degrees Celsius, a predication that still seems pretty accurate today.

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Like Tyndall, Arrhenius largely rejected the idea that manmade emissions would grow fast enough to translate to higher atmospheric carbon dioxide levels. Clearly he humankind’s ability to tear down the rainforest and burn everything on the planet. Moreover, Arrhenius welcomed the idea of warming, writing that such changes “would allow our descendents…to live under a warmer sky and in a less harsh environment than we were granted.”
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1900: Global sea level rises over 1.0 inch

1910: Atmospheric CO2 levels reach 300 PPM, matching the highest recorded historical

Politics

1910-1930

Drill, baby, drill: The opening of Texas and Persian Gulf oil fields inaugurates an era of cheap energy, with global crude oil production levels going up nearly every year since.

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Since 1750, fossil fuel consumption and cement production combined have released an estimated 370 billion metric tons of carbon dioxide into the atmosphere.
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1927: World population reaches 2.0 billion

1930: Global sea level rises over 2.0 inches

Science

1938

British engineer Guy Callendar links rising carbon dioxide levels to observable climate change.

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Callendar believed that manmade emissions were already increasing the atmospheric concentration of carbon dioxide and leading to a warmer the planet; this idea became known as the Callendar effect. Like Arrhenius, Callendar celebrated this rise in carbon dioxide, writing “… in any case the return of the deadly glaciers should be delayed indefinitely.”
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1945: Global sea level rises over 3.0 inches

Politics

1945

Following the end of World War II, the United Nations is formed.

1950: Average global temperatures are about 0.1 degrees Celsius hotter than the pre-industrial era

Politics

1955

Congress passes the Air Pollution Control Act, the first federal legislation aiming to mitigate air pollution at its source.

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The act, which was the precursor to the Clean Air Act, provided $5 million annually to the Public Health Service for “research and technical assistance relating to air pollution control.”
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Science

1956

Canadian physicist Gilbert Plass warns that the warming caused by increased carbon dioxide levels will likely result in negative consequences for the planet.

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Unlike Arrhenius and Callendar, Plass didn’t think the warming planet was a good thing; Plass’ paper, entitled “The Carbon Dioxide Theory of Climatic Change,” concluded that “the temperature rise may be so large in several centuries that it will present a serious problem to future generations.”
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1957: Global sea level rises over 4.0 inches

Science

1957

Roger Revelle, the oceanographer famous for being Al Gore’s professor at Harvard, testifies before Congress on the dangers global warming.

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Revelle testified that warming caused by carbon dioxide could turn parts of California and Texas into “real deserts” and that the Soviet Union might become a maritime power in the 21st century because of the melting Arctic. Revelle’s major contribution to climate science was in calculating the rate at which the world’s oceans absorb carbon dioxide; he demonstrated that because of the alkalinity in seawater, the ocean could only absorb about one-tenth the amount of carbon dioxide as was previously thought.
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Politics

1957

1957 is declared the International Geophysical Year, marking the end of a major information embargo between the East and the West; Sputnik is the first satellite successfully launched into Space.

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Sputnik, which represented the first major step in the space race between the United States and the USSR, lead to the creation of NASA, and ultimately to a deeper understanding of the Earth’s atmosphere and climate system.
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1960: World population reaches 3.0 billion

1962: Atmospheric CO2 levels reach 320 PPM

Science

1962

Rachel Carson publishes “Silent Spring”, which is credited for inciting the modern environmental movement.

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“Silent Spring”, first published as an article in the New Yorker, documented the effect that synthetic pesticides have on wildlife, specifically birds. The book inspired a movement that eventually led to a phase-out of many harmful pesticides and, indirectly, to the creation of the Environmental Protection Agency.
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Politics

1965

President Johnson becomes the first American president to mention climate change in a speech to Congress.

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In his speech entitled “Special Message to the Congress on Conservation and Restoration of Natural Beauty,” Johnson stated: “[t]his generation has altered the composition of the atmosphere on a global scale through radioactive materials and a steady increase in carbon dioxide from the burning of fossil fuels.”
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Science

1965

The President’s Science Advisory Committee publishes a study that warns of the dangers of rising carbon dioxide levels.

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The report, entitled “Restoring the Quality of Our Environment,” warns that increased atmospheric concentrations of carbon dioxide could result in the melting of the Antarctic ice cap, rising sea levels, warming of ocean waters, and increased acidity of fresh waters. Strikingly, while the report details the possible consequences of burning fossil fuels, it does not recommend reducing emission levels.
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Politics

1970

Under President Nixon the United States celebrates its first Earth Day, Congress passes the Clean Air Act, and the Environmental Protection Agency (EPA) and National Oceanic and Atmospheric Administration (NOAA) are both created.

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The Clean Air Act created National Ambient Air Quality Standards, which were the first set of federal regulations restricting carbon dioxide emission levels.
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1972: Global sea level rises over 5.0 inches

Politics

1972

Congress passes the Clean Water Act. The United Nations holds its first conference on the environment in Stockholm, which leads to the creation of the United Nations Environment Programme (UNEP).

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The conference called for “Governments and peoples to exert common efforts for the preservation and improvement of the human environment, for the benefit of all the people and for their posterity.” UNEP would ultimately lead to the creation of the Intergovernmental Panel on Climate Change (IPCC), the single most important source of climate change research.
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Science

1972

The crew of the Apollo 17 spacecraft takes the iconic “Blue Marble” photograph from 28,000 miles out in space, sparking awareness of the Earth’s fragile nature.

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Astronauts have described viewing the planet from space as inducing a perspective-altering experience, described as “the Overview Effect,” which produces profound feelings of awe for the Earth and an understanding that all planetary life is interconnected; the Blue Marble photograph induced a similar effect on the public.
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Science

1974

A number of scientific papers are published linking common chemicals (known as CFCs) used in spray cans, air conditioners, and refrigerators to ozone depletion.

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The most well-known of these studies, published in Nature, argued that if the emissions rate was not reduced, the atmospheric concentration of CFCs would likely increase 10 to 30 times the present level, with serious implications for the integrity of the ozone layer.
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1975: World population reaches 4.0 billion

1975: Average global temperatures are about 0.2 degrees Celsius hotter than the pre-industrial era

Politics

1975

Congress heeds the advice of scientists and holds the first hearings on CFCs and ozone depletion.

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These hearings lead to the creation of an interagency research task force, the Inadvertent Modification of the Stratosphere (IMOS), and to further funding for research on CFCs. Reports from both IMOS and the National Academy of Sciences are critical in the eventual phasing out of CFCs and the signing of the Montreal Protocol.
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Denial

1975

The billion-dollar aerosol industry creates a number of research organizations to challenge the science of ozone depletion and defend their products in the public sphere.

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One of these organizations, the Chemical Specialties Manufacturer’s Association, arranged for Richard Scorer, a professor well known for research on pollution, to tour around the United States and publicly denounce the credibility of ozone depletion work. Scorer is quoted as referring to ozone-depletion theory as “a science-fiction tale…a load of rubbish…utter nonsense.” Eventually, the Los Angeles Times exposed Scorer’s connection to the industry, calling him a “scientific hired gun.”
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Politics

1977

President Carter creates the Department of Energy (DOE), which advocates for climate change research.

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The resulting report from the DOE and JASON entitled “The Long Term Impact of Atmospheric Carbon Dioxide on Climate,” concluded that increased carbon dioxide levels could lead to food scarcity and rising sea levels, seriously threatening the global population. Conducting a review of the JASON report, meteorologist Jule Charney came upon one of the harshest realities of climate change: “A wait-and-see policy may mean waiting until it is too late.”
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Science

1979

The National Academy of Sciences (NAS) releases a report on the dangers of rising carbon dioxide levels.

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The report, entitled “Carbon Dioxide and Climate: A Scientific Assessment,” states that the release of carbon dioxide into the atmosphere will lead to a warmer planet, and the resulting “socioeconomic consequences may well be significant.”
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1980: Atmospheric CO2 levels reach 340 PPM

Politics

1981

President Reagan initiates a period of reduced government spending, stalling federally funded environmental programs.

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In line with Reaganomics, Reagan’s environmental appointees were nearly all tasked with diminishing or dismantling the agencies they were put in charge of.
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Science

1981

Both the EPA and NAS release reports arguing for the importance of addressing the problem of climate change.

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The EPA report called for addressing the climate change problem with “a sense of urgency” while the NAS report stressed for the need for further research on the subject. Faced with pressure to act on one of the two reports, Reagan would eventually advocate for further research into climate change.
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1986: Average global temperatures are about 0.4 degrees Celsius hotter than the pre-industrial era

1987: World population reaches 5.0 billion

Politics

1987

The Montreal Protocol is signed, which calls for an international phase-out of ozone-depleting chemicals.

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It’s somewhat of a mystery why Reagan signed the treaty, seeing as it doesn’t align very well with his political doctrine. It may have been that he was convinced by the science, or he saw the protocol as an insurance policy for the Earth (better safe than sorry), or Cold War politics motivated him to curb warming. Whatever the reason, it was a smart move: without the Montreal Protocol, the Earth would likely be much hotter and more volatile than it is today.
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1989: Global sea level rises over 6.0 inches

Denial

1989

Using tactics similar to those used by the tobacco industry to deny the link between smoking and cancer and by the aerosol industry to deny the link between CFCs and ozone-depletion, the fossil fuel industry creates a number of organizations to publicly challenge the soundness of climate science.

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The fossil fuel industry began recruiting a group of scientists in order to convince journalists, politicians and the public “that the risk of global warming is too uncertain to justify controls on greenhouse gases like carbon dioxide that trap the sun's heat near Earth.” Denial tactics of this nature are still very much in play today.
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1990: Average global temperatures are about 0.5 degrees Celsius hotter than the pre-industrial era

Politics

1992

The UN Framework Convention on Climate Change (UNFCC) is presented at the Rio de Janeiro Earth Summit; because of opposition from the United States, the language of the UNFCC is highly ambiguous and completely toothless.

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The UNFCC was meant to reduce greenhouse gas emissions, but the treaty essentially said that countries should figure out how to reduce emissions using other future treaties. Although the United States signs on, a Bush policy advisor wrote, “there is nothing in any of the language which constitutes a commitment to any specific level of emissions at any time.”
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Denial

1992

Members of Congress are shown a film produced by the fossil fuel industry, which demonstrates that increased carbon dioxide levels will be beneficial for the planet.

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The film, called the Greening of Planet Earth, was highly successful in convincing members of Congress that there was still no solid consensus among the scientific community regarding climate change.
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Politics

1993

Congress rejects President Clinton’s proposed energy tax, opting to tax gasoline instead, which does little to reduce emission levels.

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Clinton’s failure to pass any major environmental legislation during his presidency illustrates the difficulties in passing climate change policy. Climate change isn’t just an environmental issue; it’s also a social and economic issue, with few fast and easy solutions. While Clinton began his presidency making bold promises on environmental reform, the United States ended the decade without passing any significant green legislation.
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1994: Atmospheric CO2 levels reach 360 PPM

Science

1995

The IPCC’s second report points to concrete evidence of manmade climate change, stating that warming will likely continue in the future with potentially serious consequences. Over 1,500 scientists (including the majority of living Nobel Prize winners in science) sign onto the document “World Scientists Call for Action at Kyoto”.

Denial

1995

The climate change denial industry publishes a series of op-eds in the Wall Street Journal accusing the lead scientists of the IPCC report of having manipulated data; the attacks are unfounded.

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Fred Singer, an extremely hawkish rocket scientist with a history of having worked for the tobacco denial industry, wrote that the IPCC report had been changed in order to “to deceive policy makers and the public into believing that the scientific evidence shows human activities are causing global warming.” Despite the fact that these attacks were shown to be unfounded, they continue to circulate on the internet today.
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1996: Average global temperatures are about 0.6 degrees Celsius hotter than the pre-industrial era

Politics

1997

The Kyoto Protocol is drawn up, aiming to reduce emissions from industrialized countries by about 5.0%; the United States Congress fails to ratify it.

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At Kyoto, U.S. negotiators pushed hard on three fronts: Acceptance that the United States had already reduced its emissions through reforestation; no limits on the extent to which emissions trading could be used to fulfill treaty obligations; and commitment by developing countries to cut their own emissions. Despite these actions, the Kyoto Protocol was adopted by the European Union and a number of other countries, becoming the first major international treaty to curb emissions.
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1999: Global sea level rises over 7.0 inches

1999: World population reaches 6.0 billion

Science

2000

The term “Anthropocene” is coined to denote the present geological epoch in which global conditions are significantly affected by human activity.

Science

2001

The IPCC’s third report states “there is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities;” the report warns of the consequences of global warming with continued urgency.

Politics

2001

In response to the IPCC report, the Bush administration requests that the National Academy of Science (NAS) investigate the IPCC, and enumerate the certainties and uncertainties of climate science.

2002: Average global temperatures are about 0.7 degrees Celsius hotter than the pre-industrial era

Science

2002

The NAS publishes its report on the IPCC, finding the integrity of climate science and of the IPCC to be completely intact.

Denial

2002

A memo from a top political consultant warns members of the Republican Party that the “scientific debate is closing against us” and urges party members to “continue to make the lack of scientific certainty a primary issue in the debate.”

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The memo, written by Republican PR guru Frank Luntz, states: “Voters believe that there is no consensus about global warming within the scientific community. Should the public come to believe that the scientific issues are settled, their views about global warming will change accordingly. Therefore, you need to continue to make the lack of scientific certainty a primary issue in the debate…a compelling story, even if factually inaccurate, can be more emotionally compelling than a dry recitation of the truth."
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2005: Atmospheric CO2 levels reach 380 PPM

Science

2007

The IPCC and Al Gore share the Nobel Peace Prize “for their efforts to build up and disseminate greater knowledge about man-made climate change, and to lay the foundations for the measures that are needed to counteract such change"; the IPCC publishes its forth report.

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The forth IPCC report states that the “warming of the climate system is unequivocal,” and will very likely carry negative consequences for the planet, including: food scarcity, water stress, sea level rise, flooding, loss of biodiversity, drought, and increased intensity of extreme weather.
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Politics

2007

The Bali Road Map is passed at the 2007 UN Climate Conference; thanks to aggressive negotiations by the United States the treaty is essentially useless.

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The Road Map contained no specific commitments on the emissions reductions or environmental policy, only stating vaguely that these cuts would need to be “deep.” Still, The Bali Road Map tried to set the stage for the 2009 Copenhagen Climate Conference, and, as the agreement was signed by the United States and the largest developing countries, Bali represents an important first step towards renewed post-Kyoto collaboration on climate change.
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2008: Global sea level rises over 8.0 inches

2008: Average global temperatures are about 0.8 degrees Celsius hotter than the pre-industrial era

Denial

2009

The emails of prominent climate scientists are hacked and published, purportedly uncovering an international conspiracy to fabricate climate research; the attacks are totally unfounded.

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In an episode known as Climategate, over 1,000 emails between scientists at the Climate Research Unit of the U.K.’s University of East Anglia were made public. Despite the fact that these emails, when read in their full context, don’t amount to any evidence against the integrity of research, the credibility of climate science is significantly harmed. Climategate rumors are still circulating the internet today.
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Politics

2009

The Copenhagen Climate Change Conference is deemed a near-complete failure, with the United States refusing to sign on to any major commitments.

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What was intended to be a comprehensive international plan to curb emissions became a two and a half page document that had no concrete policy outlines. The executive director of Greenpeace UK wrote of the conference: “the city of Copenhagen is a crime scene tonight, with the guilty men and women fleeing to the airport.” The only bright spot was that 114 countries (including the United States) signed onto the Copenhagen Accord.
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2011: World population reaches 7.0 billion

Politics

2014

The United States and China reach a historic deal to collaborate in reducing greenhouse gas pollution; climate negotiations in Lima culminate with countries agreeing to outline individually tailored emissions reductions plans, called Intended Nationally Determined Contributions (INDCs).

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Historically, the United States had been unwilling to agree to emissions regulations unless developing nations pledged to curb their emissions as well; this was one of the principle reasons that most climate conferences before Lima ended in failure. With this history in mind, the agreement between China and the United States represented an enormous step forward and boded well for the Paris Climate Conference that would happen at the end of 2015.
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Science

2014

The IPCC releases its fifth report, which calls for urgency in addressing global climate change.

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The first page of the IPCC report states in bold: “Human influence on the climate system is clear, and recent anthropogenic emissions of greenhouse gases are the highest in history. Recent climate changes have had widespread impacts on human and natural systems.”
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2015: Global sea level rises about 9.0 inches

2015: Atmospheric CO2 levels reach 400 PPM, the highest concentration in recorded history

2015: Average global temperatures are about 1.0 degree Celsius hotter than the pre-industrial era

Politics

2015

President Obama unveils the final version of the Clean Power Plan, which aims to reduce U.S. carbon dioxide emissions by 32.0% from 2005 levels by 2030. In December, 196 countries come together at the Paris Climate Change Conference to sign the Paris Agreement, which pledges to limit rising temperatures “well below 2 degrees Celsius above preindustrial levels and pursuing efforts to limit the temperature increase to 1.5 degrees Celsius."

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There are two very large criticisms of the Paris Agreement: First, that the Intended Nationally Determined Contributions (INDCs) presented by all signatory countries still set the Earth on a path to warm between 2.7 to 3.5 degrees Celsius; second, the entire agreement rests on voluntary, nonbinding emissions cuts. Still, the agreement has built in mechanisms to ratchet up emissions cuts in 2020, which means that emissions cuts might very well increase in the next few years, and the deal does contain some binding elements, such as requiring that all countries participate in a system to measure the progress of their INDC goals. The bottom line is that the Paris Agreement goes much farther in addressing the problem of climate change than the global community ever has before.
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Politics

2016

The year is still young, but already policy has shown signs of lagging: in February, the Supreme Court temporarily halted the Clean Power Plan, and none of the Republicans vying for the presidency seem to understand that climate change is a serious issue.

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The Supreme Court’s decision to halt the Clean Power Plan was the first time in U.S. history that the Court stepped in to stay a regulation that was still being reviewed by a lower court. Fortunately, the Clean Power Plan has buffers built into its timeline, so the case will likely run its course through the Supreme Court before individual states are required submit their plans for achieving emissions reductions.
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Timeline Credits:

Jamieson, Dale. Reason in a Dark Time: Why the Struggle against Climate Change Failed--and What It Means for Our Future.

Oreskes, Naomi, and Erik M. Conway. Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming.

Conclusion

The presidential election this November, and the naming of a new Supreme Court Justice will be critical in determining how the battle against climate change progresses in the first half of the 21st century. If policy continues to lag, we may find ourselves to be too late to curb emissions and keep the planet’s warming below 2 degrees Celsius. The answer is simple: we know our history, so let’s make sure we don’t repeat it.