After dipping last year because of pandemic-fueled lockdowns, emissions of greenhouse gases have begun to soar again as economies open and people resume work and travel. The newly released data about May carbon dioxide levels show that the global community so far has failed to slow the accumulation of heat-trapping gases in the atmosphere, NOAA said in its announcement.
Despite a huge reduction in commuting and in many commercial activities during the early months of the pandemic, the amount of carbon in Earth's atmosphere in May reached its highest level in modern history, a global indicator released on Monday showed.
Scientists from the National Oceanic and Atmospheric Administration and the Scripps Institution of Oceanography at the University of California San Diego, said the findings, based on the amount of carbon dioxide in the air at NOAA's weather station on Mauna Loa in Hawaii, was the highest since measurements began 63 years ago.
The measurement, called the Keeling Curve after Charles David Keeling, the scientist who began tracking carbon dioxide there in 1958, is a global benchmark for atmospheric carbon levels.
Instruments perched on NOAA's mountaintop observatory recorded carbon dioxide at about 419 parts per million last month, more than the 417 parts per million in May 2020.
Because carbon dioxide is a key driver of climate change, the findings show that reducing the use of fossil fuels, deforestation and other practices that lead to carbon emissions must be a top priority to avoid catastrophic consequences, Pieter Tans, a scientist with NOAA's Global Monitoring Laboratory, said in a report on the emissions.
"We are adding roughly 40 billion metric tons of CO2 pollution to the atmosphere per year," Tans wrote. "That is a mountain of carbon that we dig up out of the Earth, burn, and release into the atmosphere as CO2 - year after year."
The amount of carbon in the air now is as much as it was about four million years ago, a time when sea level was 78 feet higher than it is today and the average temperature was seven deg F higher than it was before the Industrial Revolution, the report said.
"We are adding roughly 40 billion metric tons of CO2 pollution to the atmosphere per year," said Pieter Tans, a senior scientist with NOAA's Global Monitoring Laboratory, in a statement. "If we want to avoid catastrophic climate change, the highest priority must be to reduce CO2 pollution to zero at the earliest possible date."
The United States formally rejoined the Paris Agreement on climate change in February. Around the same time, the United Nations warned that the emission reduction goals of the 196 member countries are deeply insufficient to meet the agreement's target of limiting global temperatures from rising more than 2 degrees Celsius by the end of the century. Temperatures have already risen about 1 degree Celsius since the mid-1800s, when the use of fossil fuels became widespread.
The global warming controversy concerns the public debate over whether global warming is occurring, how much has occurred in modern times, what has caused it, what its effects will be, whether any action can or should be taken to curb it, and if so what that action should be. In the scientific literature, there is a strong consensus that global surface temperatures have increased in recent decades and that the trend is caused by human-induced emissions of greenhouse gases. No scientific body of national or international standing disagrees with this view, though a few organizations with members in extractive industries hold non-committal positions, and some have attempted to convince the public that climate change is not happening, or if the climate is changing it is not because of human influence, attempting to sow doubt in the scientific consensus. The controversy is, by now, political rather than scientific: there is a scientific consensus that global warming is happening and is caused by human activity. Disputes over the key scientific facts of global warming are more prevalent in the media than in the scientific literature, where such issues are treated as resolved, and such disputes are more prevalent in the United States than globally.
Political and popular debate concerning the existence and cause of global warming includes the reasons for the increase seen in the instrumental temperature record, whether the warming trend exceeds normal climatic variations, and whether human activities have contributed significantly to it. Scientists have resolved these questions decisively in favour of the view that the current warming trend exists and is ongoing, that human activity is the cause, and that it is without precedent in at least 2000 years. Public disputes that also reflect scientific debate include estimates of how responsive the climate system might be to any given level of greenhouse gases , how the climate will change at local and regional scales, and what the consequences of global warming will be.
Global warming remains an issue of widespread political debate, often split along party political lines, especially in the United States. Many of the issues that are settled within the scientific community, such as human responsibility for global warming, remain the subject of politically or economically motivated attempts to downplay, dismiss or deny them—an ideological phenomenon categorised by academics and scientists as climate change denial. The sources of funding for those involved with climate science opposing mainstream scientific positions have been questioned. There are debates about the best policy responses to the science, their cost-effectiveness and their urgency. Climate scientists, especially in the United States, have reported government and oil-industry pressure to censor or suppress their work and hide scientific data, with directives not to discuss the subject in public communications. Legal cases regarding global warming, its effects, and measures to reduce it have reached American courts. The fossil fuels lobby has been identified as overtly or covertly supporting efforts to undermine or discredit the scientific consensus on global warming.
Public opinion Main article: Public opinion on global warming In the United States, the mass media devoted little coverage to global warming until the drought of 1988, and James E. Hansen's testimony to the Senate, which explicitly attributed 'the abnormally hot weather plaguing our nation' to global warming. Global warming in the U.S., gained more attention after the release of the documentary An Inconvenient Truth, featuring Al Gore in 2006.
The British press also changed its coverage at the end of 1988, following a speech by Margaret Thatcher to the Royal Society advocating action against human-induced climate change. According to Anabela Carvalho, an academic analyst, Thatcher's 'appropriation' of the risks of climate change to promote nuclear power, in the context of the dismantling of the coal industry following the 1984–1985 miners' strike was one reason for the change in public discourse. At the same time environmental organizations and the political opposition were demanding 'solutions that contrasted with the government's'. In May 2013 Charles, Prince of Wales took a strong stance criticising both climate change deniers and corporate lobbyists by likening the Earth to a dying patient. 'A scientific hypothesis is tested to absolute destruction, but medicine can't wait. If a doctor sees a child with a fever, he can't wait for tests. He has to act on what is there.'
Many European countries took action to reduce greenhouse gas emissions before 1990. West Germany started to take action after the Green Party took seats in Parliament in the 1980s. All countries of the European Union ratified the 1997 Kyoto Protocol. Substantial activity by NGOs took place as well. The United States Energy Information Administration reports that, in the United States, 'The 2012 downturn means that emissions are at their lowest level since 1994 and over 12% below the recent 2007 peak.'
The theory that increases in greenhouse gases would lead to an increase in temperature was first proposed by the Swedish chemist Svante Arrhenius in 1896, but climate change did not arise as a political issue until the 1990s. It took many years for this particular issue to attract any type of attention.
In Europe, the notion of human influence on climate gained wide acceptance more rapidly than in the United States and other countries. A 2009 survey found that Europeans rated climate change as the second most serious problem facing the world, between 'poverty, the lack of food and drinking water' and 'a major global economic downturn'. 87% of Europeans considered climate change to be a very serious or serious problem, while ten per cent did not consider it a serious problem.
In 2007, the BBC announced the cancellation of a planned television special Planet Relief, which would have highlighted the global warming issue and included a mass electrical switch-off. The editor of BBC's Newsnight current affairs show said: 'It is absolutely not the BBC's job to save the planet. I think there are a lot of people who think that, but it must be stopped.' Author Mark Lynas said 'The only reason why this became an issue is that there is a small but vociferous group of extreme right-wing climate 'sceptics' lobbying against taking action, so the BBC is behaving like a coward and refusing to take a more consistent stance.'
The authors of the 2010 book Merchants of Doubt, provide documentation for the assertion that professional deniers have tried to sow seeds of doubt in public opinion in order to halt any meaningful social or political progress to reduce the impact of human carbon emissions. The fact that only half of the American population believes global warming is caused by human activity could be seen as a victory for these deniers. One of the authors' main arguments is that most prominent scientists who have been voicing opposition to the near-universal consensus are being funded by industries, such as automotive and oil, that stand to lose money by government actions to regulate greenhouse gases.
Scientific consensus See also: Scientific consensus on climate change Scientific consensus is normally achieved through communication at conferences, publication in the scientific literature, replication , and peer review. In the case of global warming, many governmental reports, the media in many countries, and environmental groups, have stated that there is virtually unanimous scientific agreement that human-caused global warming is real and poses a serious concern. According to the United States National Research Council,
here is a strong, credible body of evidence, based on multiple lines of research, documenting that climate is changing and that these changes are in large part caused by human activities. While much remains to be learned, the core phenomenon, scientific questions, and hypotheses have been examined thoroughly and have stood firm in the face of serious scientific debate and careful evaluation of alternative explanations. * * * Some scientific conclusions or theories have been so thoroughly examined and tested, and supported by so many independent observations and results, that their likelihood of subsequently being found to be wrong is vanishingly small. Such conclusions and theories are then regarded as settled facts. This is the case for the conclusions that the Earth system is warming and that much of this warming is very likely due to human activities.
Among opponents of the mainstream scientific assessment, some say that while there is agreement that humans do have an effect on climate, there is no universal agreement about the quantitative magnitude of anthropogenic global warming relative to natural forcings and its harm-to-benefit ratio. Other opponents assert that some kind of ill-defined 'consensus argument' is being used, and then dismiss this by arguing that science is based on facts rather than consensus. Some highlight the dangers of focusing on only one viewpoint in the context of what they say is unsettled science, or point out that science is based on facts and not on opinion polls or consensus.
Dennis T. Avery, a food policy analyst at the Hudson Institute, wrote an article titled '500 Scientists Whose Research Contradicts Man-Made Global Warming Scares' published in 2007, by The Heartland Institute. The list was immediately called into question for misunderstanding and distorting the conclusions of many of the named studies and citing outdated, flawed studies that had long been abandoned. Many of the scientists included in the list demanded their names be removed. At least 45 scientists had no idea they were included as 'co-authors' and disagreed with the conclusions of the document. The Heartland Institute refused these requests, stating that the scientists 'have no right—legally or ethically—to demand that their names be removed from a bibliography composed by researchers with whom they disagree'.
A 2010 paper in the Proceedings of the National Academy of Sciences analysed '1,372 climate researchers and their publication and citation data to show that 97–98% of the climate researchers most actively publishing in the field support the tenets of ACC outlined by the Intergovernmental Panel on Climate Change, and the relative climate expertise and scientific prominence of the researchers unconvinced of ACC are substantially below that of the convinced researchers'. Judith Curry has said 'This is a completely unconvincing analysis', whereas Naomi Oreskes said that the paper shows 'the vast majority of working research scientists are in agreement ... Those who don't agree, are, unfortunately—and this is hard to say without sounding elitist—mostly either not actually climate researchers or not very productive researchers.' Jim Prall, one of the coauthors of the study, acknowledged 'it would be helpful to have lukewarm a third category.'
A 2013 study, published in the peer-reviewed journal Environmental Research Letters analyzed 11,944 abstracts from papers published in the peer-reviewed scientific literature between 1991 and 2011, identified by searching the ISI Web of Science citation index engine for the text strings 'global climate change' or 'global warming'. The authors found that 3974 of the abstracts expressed a position on anthropogenic global warming, and that 97% of those endorsed the consensus that humans are causing global warming. The authors found that of the 11,944 abstracts, 3896 endorsed that consensus, 7930 took no position on it, 78 rejected the consensus, and 40 expressed uncertainty about it.
In 2014, a letter from 52 leading skeptics was published by the Committee for Skeptical Inquiry supporting the scientific consensus and asking the media to stop referring to deniers as 'skeptics.' The letter clarified the skeptical opinion on climate and denial: 'As scientific skeptics, we are well aware of political efforts to undermine climate science by those who deny reality but do not engage in scientific research or consider evidence that their deeply held opinions are wrong. The most appropriate word to describe the behavior of those individuals is 'denial'. Not all individuals who call themselves climate change skeptics are deniers. But virtually all deniers have falsely branded themselves as skeptics. By perpetrating this misnomer, journalists have granted undeserved credibility to those who reject science and scientific inquiry.'