AGU News

What Does U.S. Withdrawal from the Paris Climate Agreement Mean?

The Trump Administration has pulled the United States out of a landmark climate accord. But withdrawal does not change the science of how our planet works.

By , , and Robin Bell

This afternoon, President Donald Trump announced the decision to withdraw the United States from the Paris agreement on climate change. The agreementreached at the 21st session of the Conference of the Parties (COP 21) of the United Nations Framework Convention on Climate Change, is an historic accord negotiated in December 2015 by 190 countries—the United States included—to limit global temperature increases to no more than 2°C above preindustrial levels.

By pulling out of this international agreement, President Trump deals a serious blow to global efforts to combat climate change and mitigate its effects. The administration’s decision is one that will signal to many across our country and around the globe that the U.S. government fails to recognize the gravity of climate change and the urgency with which we must act.

The withdrawal—a political decision by the Trump administration—does not change the science of how our planet works. The American Geophysical Union (AGU) made its position clear in 2003 with the adoption of the position statement “Human-Induced Climate Change Requires Urgent Action.” While scientists continue to study the effects of climate change on the Earth and on humanity, the basic science showing that climate change has already occurred and is human-induced, due to the buildup of greenhouse gases in the atmosphere, is well understood.

Purposeful inaction by the Trump administration that runs contrary to the Paris Agreement’s goals to reduce greenhouse gas emissions and contrary to slowing the planet’s warming will mean that the effects of climate change already being felt by citizens around the world will grow more severe. A changing climate means more extreme weather events and rising sea levels, threatening human and environmental health, particularly for vulnerable populations. What’s more, we know that the U.S. economy and national security will also be negatively affected by climate change.

Scientific research into the growing threats from climate change can and will continue. As members of an international organization dedicated to promoting Earth and space science for the benefit of humanity, AGU scientists—even in the face of tight budgets—will continue their vital work to, as called for in the Paris Agreement, “strengthen scientific knowledge on climate.”

Moreover, AGU will continue its work to inform and engage diverse audiences on climate change science worldwide. Policies may change, but the science does not. To ensure economic prosperity and global health, we need a broad understanding of the societal consequences of a warming planet and honest and open communication of scientific evidence to the public and policy makers.

—Chris McEntee (email: [email protected]), Executive Director/CEO, AGU; Eric Davidson, President, AGU; and Robin Bell, President-Elect, AGU

Citation: McEntee, C., E. Davidson, and R. Bell (2017), What does U.S. withdrawal from the Paris climate agreement mean?, Eos, 98, Published on 01 June 2017.
© 2017. The authors. CC BY-NC-ND 3.0
  • Bart Wilson

    one of many good points! oh that and the people who believe “Global Warming” which is now called “Clinate Change” dont understand one thing about how our planet works or it’s history. Why was global warming re-branded as climate change? Oh, because most of the studies during the global warming crusade were found inconclusive or tampered with by the scientist themselves. Basically we are in a climate change constantly and the earth has been experiencing a warming trend since the last ice age 10k years ago. With that said, lower emissions can’t hurt, but do we have to have a global agreement to make this happen, I don’t think so, at least not one funded by the US.

  • Bob K

    I’ve yet to hear a compelling argument why this harms the environment. Will CO2 emissions be higher now because the US withdrew? If so, why? Just saying “well, yeah, just because, that’s why” isn’t a good response. Is the dying coal industry (dying because natural gas. which has lower CO2 emissions, is cheaper and more readily available than coal) going to suddenly boom now? No, it won’t. Nothing is going to change. US emissions have been improving thanks to TECHNOLOGY, not global climate treaties. These treaties do absolutely nothing. They are just talk. In the event that nations actually DO take them seriously and decrease emissions at the cost of economics, then the economic cost will reduce funds to research into alternative energy and ultimately hurt the environment even more. If you don’t believe me, just look at alternative energy ETFs after the great recession. Economics trumps everything else. You need a strong economy to fund research.

    • neeraj chhikara

      the u.s is actually responsible for 15 % of global emissions and the paris climate deal was adjusted so that usa could enter it which made the deal weaker and the usa had to born less responsibility and so now when usa is exiting from it so the deal gets more weaker coz usa and the other developed countries had to supply money to the poorer countries so that they can upgrade their technologies and pollute at less levels,now when usa had decided to back off it means that india and china has to take responsibility to consolidate the paris deal and the interesting thing is that industrial revolution has not happened in india till now, what they are experiencing is industrial evolution and their emissions are far even below russia so usa should not think of india as a culprit coz india is a poor country and can not spend so much on climate itself coz there are about 500 million poor in india who have to be taken care off and the usa would have played a role of perfect big brother in this deal and guiding whole the world to reduce themission coz usa is a superpower and when usa says something it has its implications all over the world, so usa backing off from the deal has made the paris deal close to meaningless and the deal would have to worked again if it has to make sense in some way without the usa.

      • Bob K

        Neeraj, that is a bunch of gobblety gook. Are you 8 years old? Your post looks like something an 8 year old would make. “Coz” isn’t a word an adult would use. Try capitalization and punctuation while you are at it.

        You say the US leaving “weakens” the treaty, but what does that mean? Does it mean CO2 emissions will be higher or not? If so, explain why they will be higher. If not, then you don’t have a point. The point of the treaty is to lower CO2 emissions. If that happens regardless, then the treaty is unnecessary. India isn’t going to adhere to the treaty unless it benefits India. That isn’t the fault of the US. That is the fault of India. Emissions in the US will continue to fall regardless of whether or not it signs this treaty. Remember that the US actually met the goals of the Kyoto treaty even though it didn’t sign that one either. How many nations that signed the treaty actually met the goals?

  • drseismo

    The premise of the AGU that science does not change is mind-numbing. Climate science is simply the study of a time series of weather events. Predictions of future events are simply guesses. The guesses change with time as the database increases and our understanding of the physics of earth processes changes. A position of the AGU in 2003 that climate change is human-induced and due to the buildup of greenhouse gases in the atmosphere is nearly 15 years out-of-date. Science is not static and far from settled.

    Some physicists (most recently President Rosenbaum of Caltech) now posit that nature cannot be modeled with Newtonian physics but possibly might be modeled with quantum physics. The European Organization for Nuclear Research (CERN) in December 2016 predicted a century of non-warming in which CO2 does not play a significant role. CERN concludes that climate models used by the United Nations Intergovernmental Panel on Climate Change (IPCC) to estimate future temperatures are too high and that the models should be redone. The CERN models are driven by quantum physics. The framework for the Paris Treaty has been constructed from the results of Newtonian physics, the wrong science, and the policies flowing out from the Treaty are the wrong policies.

    On a much shorter time frame, my analysis of the HadCRUT4 time-temperature data supports the long-term
    predictions from the CERN studies. The data indicate a high likelihood of the beginning of a decline in the global mean surface temperature trend line within the next decade. The first derivative of the temperature trend line has been positive for the past 20 years but has decreased in value each month for the past 20 years. The derivative is likely to become negative in the mid-2020s and increase in negative slope well into the 2030s, i.e., the mean global surface temperature will decline.

    Let me suggest what U.S. withdrawal from the Paris Climate Agreement means. It means that the U.S. will not waste trillions of dollars implementing the wrong environmental policies. It means that billions of people in
    undeveloped countries will have the opportunity to rise out of poverty because of the availability of cheap, hydrocarbon-based energy sources. It means that the economies of the U.S. and the world will prosper, and the prospect of world-wide armed conflicts will decrease.

    The emphasis now should be to roll back Ill-advised environmental regulations before they destroy the U.S.
    economy. A rational environmental protection program and a vibrant economy can co-exist. Getting out of the Paris Agreement is a huge step in the right direction.

    • Brent Lofgren

      Spectroscopy of atoms and molecules has its theoretical underpinnings in quantum mechanics, and this forms the basis for the definition of greenhouse gases. Although the QM is not explicitly modeled (doing this at the level of a climate model would be absurdly expensive), it is parameterized in the routines for radiative transfer, emission, and absorption, which lie at the root cause of not only GHG-caused climate change, but also the natural state of climate. To say that climate models are based only on Newtonian physics is false.

      • drseismo

        Thank you for your comments on parameterizing aspects of quantum mechanics in GCMs, but I did not write that climate models are based only on Newtonian physics. I stated that the framewor for the Paris Treaty has been constructed from the results of Newtonian
        physics, which is a true statement. The fundamental unanswered questions can be simply stated. (1) Do the GCMs parameterize aerosol production based on the CERN CLOUD study, and (2) are GCM predictions still widely divergent?

    • Helena Galvão

      drseismo r u just posing as a scientist?

      • Bob K

        Lol, are you (not “r u”) posing as a 5th grader? Learn to type in longhand English. This isn’t a text message to your bestie. As a scientist myself, I’d believe drseismo is a scientist long before I’d believe you were an adult.

    • Bart Wilson

      here here

  • bookspeople

    Put 1000 passengers and 850 crew on a drifting cruise ship. At regular intervals toss in another 20 or so. One day, noticing there is actually nobody in the captain’s chair, crew and passengers split into numerous mutually hostile camps. Various people wrestle fiercely and pointlessly over the captain’s hat. Myths arise, explaining why those other passengers should be fed to the Great Shark or why there really never was any land. Fights, feuds and gang wars arise as supplies become scarce. Frustrated groups start fires and drill holes in the hull. One day, the professional lookouts notice the ship is drifting toward a reef and will crash within a year, but contrive plans to divert the ship with sails and sweeps if everyone thinks clearly and works together for the common good. They are right! Within a year, the reef fish have a fine new sunken habitat and thank the Great Shark for their bounty.