How long have we known about human-caused global warming?
Dear EarthTalk: When did scientists first discover that carbon dioxide levels were rising in the atmosphere due to human activity and that this could cause global warming?
—Barbara Mickelson, Sumter, SC
The Earth’s climate is continually changing. Since the planet was born some 4.5 billion years ago, it has undergone ice ages and warm periods due to natural changes in its orbit around the sun and other factors on its surface. But since the Industrial Revolution, humans have been the main factor in the Earth’s warming. Since pre-industrial times, the Earth’s surface has warmed some 1.5 degrees celsius. And with 2.4 million pounds of carbon dioxide (CO2) being released into the air every second, we are on track to get a lot warmer still. So when did we realize global warming was happening and that this round at least is human-caused?

The science behind climate change was first understood by Swedish chemist Svante Arrhenius in 1896; he thought the results would be positive for humans. Arrhenius realized that burning fossil fuels would have a greenhouse effect on the planet and would likely warm the planet by several degrees. Throughout the 20th century, the planet’s human population increased by more than 280 percent and CO2 production increased by more than 1160 percent. As the climate warmed, more and more scientists started to realize that human activity must be to blame. By 1959, worry among the scientific community increased as some scientists projected that CO2 would increase with potentially “radical” effects on climate.
But it wasn’t until 1995 that the Intergovernmental Panel on Climate Change gave a definitive statement that humans are responsible for post-industrial global warming. As of 2010, there was a 97 percent consensus among scientists that climate change was caused by humans.
So why haven’t we fixed the situation? The answer may partially lie in the part large energy corporations played in swaying public opinion. As InsideClimate News reports, ExxonMobil was aware that anthropogenic climate change was likely as early as 1977. Since then, ExxonMobil has spent more than $30 million on think tanks that promote climate denial. While it can perhaps be pardoned for opposing climate change research when the science was still inconclusive, ExxonMobil continued funding climate change denial groups as late as 2009—well after our carbon emissions were established as the cause of climate change. ExxonMobil even helped found the “Global Climate Coalition,” a lobbying group that prevented the U.S. from taking action against limiting greenhouse gas emissions.
And ExxonMobil isn’t alone. Koch Industries, a Kansas-based multinational with big investments in oil and other fossil fuels, has donated over $88 million to climate change denial. Chevron, BP and others also fund such efforts. The actions of these companies have had a profound impact on public opinion. According to a recent survey by the Pew Research Center, the U.S. has the highest carbon emissions per capita in the world but “is among the least concerned about climate change and its potential impact.”
Confronting ExxonMobil and other corporations that give misleading information to the public is important because this issue affects all of us. Non-profits like Greenpeace are trying to make sure oil companies stop obfuscating the truth and start promoting cleaner energy. Regardless, our commitments at the Paris climate accord have the U.S. and the rest of the world on the right path toward reducing emissions, no matter what the oil companies say about it.
Steven Litvintchouk
September 19, 2016 @ 3:01 pm
It has nothing to do with oil companies.
Advertising campaigns and political campaigns can’t sell a product or a candidate or an idea to a public that just doesn’t like it.
The reason why Americans aren’t thrilled about fighting global warming is because millions of their *jobs* will be jeopardized, as will an energy-intensive way of life that Americans have long cherished.
America uses about 2 terawatts–2 trillion watts–of power on a typical weekday. The average wind turbine puts out about 1.4 megawatts. You’re not going to power America’s 2 terawatts with windmills and solar panels. Never. (Grab a calculator or spreadsheet and run the numbers for yourself.) It would require massive conservation and doing without.
We tried this “Turn down your thermostats and shiver in the dark” stuff in the 1970s during the Carter Administration, and Americans hated it.
Millions of American blue-collar workers in the fossil fuel industry, the trucking industry, and heavy industries that depend on cheap energy are very likely to lose their jobs. This progressive “clean energy economy” is a society of geeks, nerds, Hollywood actresses, and liberal columnists. There’s no room in it for Americans who work with their hands.
Global warming is definitely real. The great chemist, Svante Arrhenius first wrote about it back in 1903. Here’s a TV documentary about it from the 1950s, directed by Frank Capra:
https://www.youtube.com/watch?v=0lgzz-L7GFg
But back then, we weren’t too worried because we expected “clean, safe atomic energy” to replace the burning of fossil fuels and save them for the petrochemical industries instead. The same environmentalists who fight fossil fuels now fight nuclear power, and Greenpeace, IIRC, even launched a pre-emptive attack on thermonuclear fusion, even though that’s still in the research stage. Just where does Greenpeace expect those 2 terawatts of power to come from?
Let’s not kid ourselves. The solution to global warming may well mean the end of America as an industrial superpower: Air travel once again restricted to the wealthy. Train straphanging instead of private cars. Millions of permanently unemployed blue-collar workers.
Don’t expect Americans to like it, much less embrace it.
Some realities are really unpleasant.
Holly Carlson
March 20, 2017 @ 4:10 pm
You make some very good points, Steven, but certainly you do not believe it is only about Americans and how Americans view the issue. There’s a whole lot of planet beside America that is polluting a whole lot more than America. Draconian measures foisted upon America is not going to solve anything. Regardless of facts and figures on petrol-based fuel for the planet’s energy needs and any connection to global warming, there is no valid reason not to go with nuclear, providing we can make it safe enough and avoid Fukashimas by ensuring they are robust enough to withstand any natural disaster. What are all the other large economies willing to sacrifice for the cause of slowing/stopping any warming that may be occurring?