The most ardent foes of climate policy in the Trump administration dreamed of staging a grand climate science debate. They called it a “red team/blue team” exercise, a term borrowed from military strategy games, and it was designed to test the proposition that fossil fuel pollution put the planet at risk.
Critics blasted the debate idea as a gambit to boost the arguments of climate deniers and belittle the widespread scientific consensus on the harm of carbon pollution. And, at a time when polls showed the number of Americans who thought the government was doing too little on the environment was at a 12-year high, President Donald Trump’s advisers ended up quashing the plan as politically risky.
But in a new book, “Unsettled: What Climate Science Tells Us, What it Doesn’t and Why it Matters,” the architect of the red team/blue team idea has resurrected it in a new form. The book, by physicist Steven Koonin, a former chief scientist at BP who did a two-year stint in the Obama Administration, already has won praise from anti-climate-action bloggers, columnists and The Wall Street Journal. “Any reader would benefit from its deft, lucid tour of climate science, the best I’ve seen,” wrote Journal columnist Holman W. Jenkins Jr. about the book, which is scheduled for publication Tuesday.
In “Unsettled,” Koonin describes himself as a scientist who focused on alternative energy—first at BP, and later, as part of President Barack Obama’s team—but who began to have doubts about climate science after leaving the Obama administration. Beginning in 2013, when Koonin was selected to lead the American Physical Society’s review of its statement on climate change, Koonin writes, he became “not only surprised, but shaken by the realization that climate science was far less mature than I had supposed.”
He argues that the impact of human influence on the climate is too uncertain, and may be too small, to merit costly action to reduce fossil fuel use. Society, he says, will be able to adapt to warming.
Scientists who have spent their careers studying climate science said that Koonin’s critiques are superficial, misleading and marred by overgeneralization. The science at the core of “Unsettled” is fatally out of date, they say, and is based on the 2013 physical science report of the Intergovernmental Panel on Climate Change (IPCC).
Since then, climate scientists have continued to learn more about the intensity and potentially catastrophic disruption of a warming climate. And while a decade ago, the effects of climate change still seemed a future threat, its impacts—sea level rise; shrinking glaciers; more extreme and frequent storms; drought and wildfire—already are being felt around the world.
The most recent scientific evidence, which will be covered in the IPCC update due out in August, has increased researchers’ confidence that human activity is the driving force in the current warming. Climate attribution studies in the last five years have shown that recent heat waves would have been all but impossible without the effect of greenhouse gas pollution. Other new research suggests that global warming has intensified extreme rainfall over parts of North America, and that overheated oceans are increasing the intensity of the tropical storms. Koonin’s book does not take these studies into account, and when he does cite recent studies, stresses their uncertainties rather than the findings, which affirm humanity’s role in the planet’s changes.
“The bottom line is that despite uncertainties in the magnitude and patterns of natural climate variability, human-caused climate change fingerprints have been identified in pretty much every aspect of climate change scientists have looked at,” said Benjamin Santer, an atmospheric scientist and leading climate modeler at Lawrence Livermore National Laboratory.
Climate scientists also noted that Koonin, a theoretical physicist, was skeptical of consensus climate science long before the American Physical Society review.
“What he does is he just takes potshots,” said Don Wuebbles, an atmospheric scientist at the University of Illinois, who has helped lead the National Climate Assessment, which Koonin’s book criticizes roundly. “He pulls one figure out of context, and then makes a whole chapter on it.”
Many climate action advocates who are familiar with Koonin’s long-held views are dismayed to see them repackaged as a book, just as President Joe Biden’s administration is seeking to restore the place of the scientific consensus in policymaking after a four-year absence.
“He’s not a fearless ‘truth teller,'” said Santer, referring to a Wall Street Journal headline on a piece about Koonin’s book. “He’s muddying the waters here. He’s making it much more difficult to make informed decisions.”
‘We Can’t Fry Enough Potatoes’
Koonin, who did not respond to a request for an interview, writes that his book is an effort to increase understanding of scientific uncertainties at a time when the government is making “trillion-dollar decisions about reducing human influences on the climate.”
“The impact of human influences on the climate is too uncertain (and very likely too small) compared to the daunting amount of change required to actually achieve the goal of eliminating net global emissions by, say, 2075,” Koonin writes. (The net-zero target of many of the largest of the 197 nations that have signed the Paris climate agreement, including the United States, is 2050.)
“For me,” Koonin concludes, “the many certain downsides of mitigation outweigh the uncertain benefits: the world’s poor need growing amounts of reliable and affordable energy, and widespread renewables or fission are currently too expensive, unreliable, or both.”
Koonin writes that he would wait until the science became more settled or technologies became more feasible before embarking on aggressive policy to eliminate carbon emissions. “I believe it is a responsibility, almost an act of conscience, to portray without bias just how settled—or unsettled—the science truly is,” he writes.
The fact that Koonin was an undersecretary for science in President Barack Obama’s Department of Energy is highlighted on the cover of Koonin’s book. Koonin was tapped for the position by Obama’s first secretary of energy, Nobel Prize-winning physicist Steven Chu.
In 2007, Chu was director of the Lawrence Berkeley National Laboratory when Koonin’s research program at BP selected the lab and the University of California, Berkeley, to lead an advanced biofuels research program that would receive $500 million in corporate funding over 10 years—at the time believed to be the largest-ever corporate sponsorship of university research.
Two years later, when Chu headed to Washington to head Obama’s Department of Energy, he asked Koonin to join him, specifically because of Koonin’s willingness to challenge conventional wisdom, Chu recalled.
“Unlike many people, I didn’t want to have a department where everybody believed exactly as everybody else,” said Chu, a professor of physics and molecular and cellular physiology at Stanford University. “If there’s a bandwagon moving along, you need a bunch of people to say, ‘Wait a minute, how do you know this? How do you know that?’ I think Koonin is of that ilk. He loves to be the curmudgeon type.”
Earlier in Koonin’s career, in 1989, that inclination led him to prominence, as one of a group of scientists who successfully debunked the claims of a University of Utah team who reported that they had discovered “cold fusion”—a breakthrough that, had it proved real, would have transformed energy production.
Later, Koonin became vice president and provost of the California Institute of Technology, a position he held for nine years before joining BP. By 2004, the oil giant was four years into a public relations campaign to rebrand itself as a “Beyond Petroleum” company. In a 2007 speech at the University of California, San Diego’s Center for Energy Research, Koonin said his job at BP was to help plot and implement the company’s long-term technology strategy.
“The way I like to think of it is to figure out what Beyond Petroleum really means,” said Koonin, who led decisions on the company’s investments in alternative energy research, which at the time included advanced biofuels, carbon capture and storage, synthetic fuels and alternative technologies and materials for solar energy. In a 2007 profile of Koonin in Science magazine, he was quoted saying he had doubts about climate science before joining the company. “I was more skeptical about climate change a few years ago. Now I’ve come round more toward the IPCC view,” he said.
Keep Environmental Journalism Alive
ICN provides award-winning climate coverage free of charge and advertising. We rely on donations from readers like you to keep going.
But in his speech at UC, San Diego, although he agreed climate change was occurring, with humans playing some role, Koonin stressed that future impacts were uncertain. Scientists have always taken note of uncertainties in how severe future impacts of climate change will be; but there is an overwhelming consensus among scientists who, unlike Koonin, believe that risks will increase without action to reduce fossil fuel pollution.
In a world with a growing population and increasing energy demand, where millions lacked access to power, Koonin said that oil, natural gas and coal would dominate the world’s fuel supply for decades to come.
Many points from that speech of 14 years ago appear in Koonin’s new book. On biodiesel from waste oil, for example, he writes in “Unsettled”: “We can’t fry enough potatoes to make a significant difference in emissions.” On the viability of alternatives to fossil fuels, he says, “It’s true that ‘there are no silver bullets,’ but some bullets have a bigger caliber than others.”
While at BP Koonin, as he does today, advocated research into approaches typically favored by oil companies and Republicans opposed to fundamental change in energy supply. They include carbon capture and storage, advanced nuclear energy, and biofuels and geoengineering ideas, like seeding the atmosphere with aerosol particles to increase Earth’s reflectivity.
A Red Team, Blue Team Rehearsal
Even while he was in the Obama administration, Koonin was raising doubts about the climate science consensus. Wuebbles recalled getting a call from Koonin for a meeting soon after he took office. “When I got there, all he wanted to do was argue about his views on climate change,” said Wuebbles, who would later become a science adviser to the Obama White House himself. “And it was just nonsense. And I did say ‘No, this is not right.’ And it’s been like that ever since.”
Two years after Koonin left government, as the founding director of the Center for Urban Science and Progress at New York University, he had an experience delving into climate science that he recounts in his book as pivotal. As an active member of the APS, the biggest professional group of physicists, Koonin took a leading role in an effort to revise the society’s official statement on climate change.
The first physical society statement on climate change, in 2007, had been controversial, with a small but vocal number of the 50,000-member society objecting to it, in part because it included the phrase, “the evidence is incontrovertible.”
The dissenters included climate skeptics William Happer, a Princeton physicist, and the late S. Fred Singer, who published an open letter in Nature calling for a withdrawal of the statement. The APS did not agree, but the society’s policy was to review such statements periodically and the leadership decided that the IPCC’s release of its updated assessment of the physical science of climate change in 2013 was the right time to do it.
Koonin, vice chairman of the society’s Panel on Public Affairs, became chairman of the subcommittee that launched the process and, in a preview of his later idea for a red team, blue team debate, spearheaded plans for a similar event at NYU in January 2014. Three mainstream climate scientists, including Santer, faced off against three prominent climate contrarians: Richard Lindzen, who had recently retired from the Massachusetts Institute of Technology; John Christy, of the University of Alabama, and Judith Curry, of the Georgia Institute of Technology.
The contrarians made the same arguments that they had been making on Capitol Hill and elsewhere for years about the uncertainty of climate science. For example, Christy, an atmospheric scientist, focused on how the climate models did not agree with the temperature records that he and his laboratory had derived from satellite instrument readings.
After the debate, according to an APS spokesman, Koonin proposed a revision of the society’s climate statement that was not accepted by the panel, “following which, Koonin chose to resign,” the spokesman said. The spring meetings of the panel included contentious debate on the subject, the minutes show, and Koonin gave up his leadership role in APS.
The APS spokesman added, “The review continued, adhering to the standard process, and resulted in the 2015 Statement on Earth’s Changing Climate.”
That statement, although it dropped the word “incontrovertible,” was a strong affirmation of the scientific consensus “that human influences have had an increasingly dominant effect on global climate warming.” It also reiterated the society’s previous call for action to reduce emissions of greenhouse gas and to increase resiliency, while supporting research on technology to mitigate human climate impact.
Soon after his resignation from APS, Koonin published his own statement in a September 2014 editorial in The Wall Street Journal entitled, “Climate Science is Not Settled.”
New Influence in the Era of Trump
Koonin’s opinions did not have much sway with his former colleagues in the Obama administration, which the following year signed on to the Paris climate agreement. But after President Donald Trump took office in 2017, Koonin’s views suddenly gained new influence.
He published another column in The Wall Street Journal in April 2017, proposing his idea for the “red team/blue team” debate on climate science, similar to the one at N.Y.U. “The irony is he already had a red team/blue team debate, and the red team lost,” said Santer.
But among those who were excited by the idea was Trump’s first Environmental Protection Agency administrator, Scott Pruitt. According to the draft of a press release EPA staff circulated in November 2017 and later obtained by Buzzfeed, Pruitt’s EPA planned to select scientists to be on the anti-climate science “red team” who would pick apart the National Climate Assessment, the government’s legally required review of the state of the science. In effect, the government and the outside scientists who were working on the assessment would be the “blue team.”
Koonin says in his book that he was not a supporter of Trump, but Trump EPA officials did reach out to him to see if he could assist in the red team/blue team effort.
“Dr. Koonin is well respected and [a] former Obama Administration official,” said Ryan Jackson, who was EPA’s chief of staff at the time and is now in charge of government affairs for the National Mining Association. “When trying to recruit individuals to serve either at EPA or volunteer to serve on EPA science boards, Dr. Koonin was one of many individuals I reached out to to see if he would be interested in contributing in a number of ways and not simply on climate policy.”
According to reporting by The New York Times, then-White House Chief of Staff John Kelly put a stop to Pruitt’s red team/blue team plan, which he viewed as ill-conceived.
‘People See it Happening in All Kinds of Ways’
It’s unclear whether Koonin’s latest packaging of his arguments will have any influence on public policy, at a time when the president is embarking on policy aimed at cutting U.S. carbon emissions in half by 2030 and even House Republicans are unveiling their own climate plans.
Jenkins, at the Journal, argues that policymakers should listen to Koonin. He has written about the book not once but twice, and the paper gave it a favorable review, as did Forbes. For the past two weeks it has been among the top 10 best-selling science & math books on Amazon.
Chu, who said he has not read the book, said he believes alternative technology like increased battery storage for renewable energy sources is more advanced than Koonin perhaps realizes: He is currently an adviser to a company that is working on electric vehicle battery technology. And, Chu said, some of the latest climate science, too new to be a part of the most recent assessments from IPCC (2013 and 2014) and the U.S. Global Change Research Program (2017 and 2018) has addressed many uncertainties and deepened scientists’ understanding of climate change considerably.
“The science that’s come out more recently is making me more scared,” said Chu. “But what it’s doing is one by one trying to look at all these points we’re not sure of, and trying to understand these things. And so I think that part is getting stronger and stronger.”
Chu maintains that skeptics like Koonin play an important role in the scientific community. “This is a lot of what keeps science honest,” said Chu.
But Chu said he also believes the world needs to act on climate change, “This is where Steve is missing the point, and this is where he and I differ,” said Chu.”It has to do with risk management. If there’s a reasonable chance that some very bad things are going to happen, shouldn’t you take steps?”
Kerry Emanuel, a meteorologist at Massachusetts Institute of Technology, and author of leading studies on hurricanes, said he doubts that Koonin’s book will have the kind of impact that it once would have had, simply because public opinion has shifted enough to support a call for climate action.
“Of course, it’s going to be used by people who think there’s no big deal,” Emanuel said. “Politicians will use anything. But I think looking at the grand scheme, it will make very little difference at all. Because those people are becoming a dwindling minority, even amongst Republicans.”
He added, speaking of climate change, “The fact of the matter is that people see it happening in all kinds of ways with their eyes.”
Bob Berwyn contributed to this report.
Reporter, Washington, D.C.
Marianne Lavelle is a reporter for Inside Climate News. She has covered environment, science, law, and business in Washington, D.C. for more than two decades. She has won the Polk Award, the Investigative Editors and Reporters Award, and numerous other honors. Lavelle spent four years as online energy news editor and writer at National Geographic. She spearheaded a project on climate lobbying for the nonprofit journalism organization, the Center for Public Integrity. She also has worked at U.S. News and World Report magazine and The National Law Journal. While there, she led the award-winning 1992 investigation, “Unequal Protection,” on the disparity in environmental law enforcement against polluters in minority and white communities. Lavelle received her master’s degree from Columbia University Graduate School of Journalism, and is a graduate of Villanova University.
Who published why scientists disagree about global warming? ›
This volume, like past NIPCC reports, is edited and published by the staff of The Heartland Institute, a national nonprofit research and educational organization newly relocated from Chicago to suburban Arlington Heights, Illinois.What is the best conclusion about climate change? ›
In conclusion, climate change is the most significant problem facing the world. Global warming is increasing day by day. If we cannot prevent it as soon as possible, our world will face undesirable consequences.Which is a more reliable source of information on climate change? ›
Credible sources. The Intergovernmental Panel on Climate Change (IPCC) assesses the peer-reviewed literature on climate change every 5 to 6 years. Their assessment reports, which are also peer-reviewed, are a credible source of information.What does research say about climate change? ›
The current scientific consensus is that: Earth's climate has warmed significantly since the late 1800s. Human activities (primarily greenhouse gas emissions) are the primary cause. Continuing emissions will increase the likelihood and severity of global effects.Do scientists agree on what causes climate change? ›
Yes, the vast majority of actively publishing climate scientists – 97 percent – agree that humans are causing global warming and climate change.When did scientists warn us about climate change? ›
The present state of climate change
Global greenhouse gas emissions have increased by about 40 percent over the last three decades, despite ringing alarm bells, when more than 1,700 scientists signed the World Scientists' Warning to Humanity in 1992.
Yes. While we cannot stop global warming overnight, we can slow the rate and limit the amount of global warming by reducing human emissions of heat-trapping gases and soot (“black carbon”).Why is climate change bad conclusion? ›
Climate change poses a growing threat to sustainable development. The expected effects of climate change could seriously compromise the ability of the agriculture sectors to feed the world, and severely undermine progress toward eradicating hunger, malnutrition and poverty.How can we stop global warming conclusion? ›
To reduce global warming we can contribute by reducing the production and concentration of greenhouse gases in the atmosphere. We need to curb usage of gasoline, electricity and other activities including mining and industrialization that cause global warming. Another way to reduce global warming is through recycling.Who is the biggest contributor to climate change? ›
Fossil fuels – coal, oil and gas – are by far the largest contributor to global climate change, accounting for over 75 per cent of global greenhouse gas emissions and nearly 90 per cent of all carbon dioxide emissions. As greenhouse gas emissions blanket the Earth, they trap the sun's heat.
Who is the biggest cause of climate change? ›
Human activity, such as burning fossil fuels and changing how we use the land, is the leading cause of climate change.What is the No 1 cause of climate change? ›
Human activity is the main cause of climate change. People burn fossil fuels and convert land from forests to agriculture. Since the beginning of the Industrial Revolution, people have burned more and more fossil fuels and changed vast areas of land from forests to farmland.Is it too late to stop global warming? ›
Global average temperatures have risen and weather extremes have already seen an uptick, so the short answer to whether it's too late to stop climate change is: yes.Is climate change a threat to our future? ›
“It shows that climate change is a grave and mounting threat to our wellbeing and a healthy planet. Our actions today will shape how people adapt and nature responds to increasing climate risks.” The world faces unavoidable multiple climate hazards over the next two decades with global warming of 1.5°C (2.7°F).Do meteorologists believe in climate change? ›
The vast majority of members of the American Meteorological Society agree that recent climate change stems at least in part from human causes, and the agreement has been growing significantly in the last five years.What does the majority of climate scientists believe is the cause of the current? ›
The greenhouse gases contribute to the greenhouse effect by absorbing infrared radiation from the piles of the earth's surface. Climate scientists believe that the enhancement of the greenhouse effect is the major cause of climate change on earth.When did humans start worrying about global warming? ›
Many climate scientists were now convinced that the rise was likely to continue as greenhouse gases accumulated. By around 2000, some predicted, an unprecedented global warming would become apparent. Their worries first caught wide public attention in the summer of 1988, the hottest on record till then.Who warned us about climate change? ›
Eunice Newton Foote's 1856 research foreshadowed how both climate change and women would be treated by society for decades.Are we in a climate emergency? ›
The world is in a state of climate emergency, and we need to shift into emergency gear. Humanity's burning of fossil fuels has emitted enough greenhouse gases to significantly alter the composition of the atmosphere and average world temperature has risen between 1.1 and 1.2°C.How long until climate change is irreversible? ›
of aggressive climate change policies is that humanity is always about 10 years away from either catastrophic climate change, or some greenhouse gas emission “tipping point” at which such change will become inevitable.
How long will it take for climate change to reverse? ›
It could take as long as 1,000 years after a complete halt of greenhouse gas emissions for environmental measures like sea level and ocean surface temperature to return to pre-industrial levels [source: NOAA]. In addition, other factors besides greenhouse gas emissions can contribute to global warming.How much time do we have left for climate change? ›
Climate change report: Earth has 11 years to avoid the worst scenarios Carbon dioxide emissions are rebounding after a dip in 2020, and researchers say that at the current rate, Earth's "carbon budget" will be exhausted in roughly 11 years.Why is climate change a negative thing? ›
Impacts. Humans and wild animals face new challenges for survival because of climate change. More frequent and intense drought, storms, heat waves, rising sea levels, melting glaciers and warming oceans can directly harm animals, destroy the places they live, and wreak havoc on people's livelihoods and communities.What is the problem behind climate change? ›
Climate change is disrupting weather patterns, leading to more extreme and frequent droughts and flooding events that directly threaten harvests. The warming climate is contributing to rising populations of insect pests that eat a higher share of crop yields.How damaging is climate change? ›
Climate change is already impacting health in a myriad of ways, including by leading to death and illness from increasingly frequent extreme weather events, such as heatwaves, storms and floods, the disruption of food systems, increases in zoonoses and food-, water- and vector-borne diseases, and mental health issues.How can we stop climate change facts? ›
- Make your voice heard by those in power. ...
- Eat less meat and dairy. ...
- Cut back on flying. ...
- Leave the car at home. ...
- Reduce your energy use, and bills. ...
- Respect and protect green spaces. ...
- Invest your money responsibly. ...
- Cut consumption – and waste.
- Ending Our Reliance on Fossil Fuels.
- Greater Energy Efficiency.
- Renewable Energy.
- Sustainable Transportation.
- Sustainable Buildings.
- Better Forestry Management and Sustainable Agriculture.
- Conservation-Based Solutions.
- Industrial Solutions.
China was the biggest emitter of carbon dioxide (CO₂) emissions in 2021, accounting for nearly 31 percent of the global emissions. The world's top five largest polluters were responsible for roughly 60 percent of global CO₂ emissions in 2021.Which country is worst for climate change? ›
The top 10 largest emitter countries account for 67.6% of the world total. Since 2006, China has been emitting more CO 2 than any other country.Is the US the biggest contributor to climate change? ›
Because fossil fuels are widely used and traded globally, reducing U.S. domestic supply is unlikely to have much effect on global GHG emissions. However, the United States is the world's second largest GHG emitter and 77% of U.S. GHG emissions come from fossil fuel combustion.
What are the 3 main natural causes of climate change? ›
These have been caused by many natural factors, including changes in the sun, emissions from volcanoes, variations in Earth's orbit and levels of carbon dioxide (CO2).What are the 3 main causes of global warming? ›
- carbon pollution.
- climate change.
- Electricity Generation and Heat Production. The first sector on our list is electricity generation and heat production, which accounts for approximately 28% of the world's greenhouse gas emissions. ...
- Transportation. ...
- Industry. ...
- Commercial and Residential Emissions. ...
Burning fossil fuels for electricity and heat is, by far, the main driver of climate change.Will the Earth become uninhabitable? ›
With the UN having confirmed a temperature rise of 1.5°C compared to the pre-industrial era, the climatic, human, food and economic consequences will be unprecedented. On 9 March, NASA published a world map showing the regions of the planet that will no longer be habitable in 30 to 50 years' time due to climate change.Will climate change cause human extinction? ›
The risk that global warming could lead to human extinction is “dangerously under explored”, climate scientists have warned. As the globe heats up and emissions continue to rise, a team of international researchers has urged governments to start paying attention to “worst case scenario” outcomes.Will trees stop global warming? ›
Trees are natural carbon capture and storage machines, absorbing carbon dioxide (CO2) in the atmosphere through photosynthesis then locking it up for centuries. It's why reforestation and afforestation are touted as key solutions to the climate crisis.What is the greatest threat to humanity? ›
Climate change the greatest threat the world has ever faced, UN expert warns.Is climate change the biggest threat facing humanity today? ›
Climate change is the biggest threat facing humanity today. At Islamic Relief we witness the impact of extreme weather events in our work all over the world.What state is best for climate change? ›
Overall, the top five best states concerning climate resilience are California, Maine, New York, Vermont and Massachusetts. The top five worst-ranking states were Nebraska, West Virginia, Mississippi, Alaska and, finally, Louisiana. Each of the five environmental categories held a certain percentage of the total score.
What percentage of meteorologists believe in global warming? ›
By 2017, 95 percent of TV weathercasters agreed that the climate was indeed changing. By 2020, 80 percent acknowledged that human activity was a major reason.What percentage of meteorologists believe in climate change? ›
About 97 percent of climate researchers believe that climate change is real and caused by humans, according to a recent report from the National Academy of Sciences.Why trust climate science? ›
Public trust in climate science is deemed necessary for ensuring that the public and governments that get their mandates from the public adopt climate-friendly behaviours and policies to avert the devastation predicted to result from further global warming (Perkins et al., 2021).Why scientists disagree about global warming review? ›
The authors point to four reasons why scientists disagree about global warming: a conflict among scientists in different and often competing disciplines; fundamental scientific uncertainties concerning how the global climate responds to the human presence; failure of the United Nations Intergovernmental Panel on ...Who is the scientist who predicted global warming? ›
In the new study, Geoffrey Supran and Naomi Oreskes of Harvard, and Stefan Rahmstorf of the Potsdam Institute, carried out a quantitative analysis of global warming projections made or recorded by Exxon scientists between 1977 and 2003.Who was the first scientist to warn about global warming? ›
In 1896, a seminal paper by Swedish scientist Svante Arrhenius first predicted that changes in atmospheric carbon dioxide levels could substantially alter the surface temperature through the greenhouse effect. In 1938, Guy Callendar connected carbon dioxide increases in Earth's atmosphere to global warming.What is the opposing view of global warming? ›
Some reject the idea that human-caused climate change exists; others have argued that human-made climate change is occurring but that the extent to which climate is changing and the precise impact of human activity is uncertain.Why is it difficult for scientists to fully understand the Earth's climate? ›
The Earth's climate system is stochastic and cannot be understood in this way. That is to say that whilst there are many factors that can be shown to influence climate, it also has a completely random component. This means that it must be understood in terms of probabilities and risk, not in absolutes.Why do scientists disagree? ›
There are many reasons why studies disagree.
Scientific studies often come to different conclusions about the same topic. Sometimes, studies have different results even when scientists try to use the same methods and data. Scientists try to share their methods and data so that others can redo their studies.
Wildfires, heat waves, droughts, and inland flooding continue breaking records. Without immediate emissions reductions, these impacts will worsen. Globally, food and water shortages could displace hundreds of millions of people, increasing conflict and war. Entire regions of the world may become uninhabitable.
Who is the world's number one polluter? ›
China was the biggest emitter of carbon dioxide (CO₂) emissions in 2021, accounting for nearly 31 percent of the global emissions. The world's top five largest polluters were responsible for roughly 60 percent of global CO₂ emissions in 2021.Why is january 2023 so warm? ›
Why was it so warm? While January 2023 may be most remembered for the ceaseless deluge of rain that eased California's drought conditions, the same jet stream configuration also flooded the United States with mild, Pacific air.What happens if we do nothing to stop climate change? ›
What happens if we do nothing to stop climate change? If we do not take further action to stop climate impacts we're already experiencing, the planet is likely to see global temperatures rise by 2-4 °C (3-7 °F) by the end of the century.When did global warming first start? ›
Scientists generally have argued that man-made climate change caused by greenhouse gas emissions began in the late 1800s.Do you think that global warming can be reversed? ›
Yes. While we cannot stop global warming overnight, we can slow the rate and limit the amount of global warming by reducing human emissions of heat-trapping gases and soot (“black carbon”).Why isnt global warming a big deal? ›
Why a half-degree more is such a big deal. Climate change is breeding storms with heavier rainfall, flooding farms — such as this one, which grows cotton. Climate change is breeding storms with heavier rainfall, flooding farms — such as this one, which grows cotton.