In today’s Academic Minute, Dr. Pushker Kharecha of Columbia University’s Earth Institute explains how a small shift in the timing of peak CO2 emissions will shape the Earth’s climate for centuries.
Pushker Kharecha is a research scientist at the NASA Goddard Institute for Space Studies and Columbia University’s Center for Climate Systems Research. His research at GISS focuses on the global carbon cycle, which is the exchange of carbon among the different components of the climate system (atmosphere, land, and ocean). He holds a Ph.D. in geosciences and astrobiology from Penn State University.
Dr. Pushker Kharecha – Peak CO2 Emission
Numerous lines of evidence show that the main cause of global warming in recent decades has been human-caused emissions of greenhouse gases by fossil fuel burning and deforestation. Carbon dioxide, or CO2, is by far the biggest culprit, and its effects last on the order of a thousand years, because of the very long time that it stays in the air.
Our energy infrastructure also has a relatively long life; on average, every new coal or gas-fired power plant we build will emit CO2 for about 50 years. Thus, our decisions on how to produce energy today will determine the fate of many future generations of humans, and countless other species.
In recent work, my colleagues and I present evidence that if global CO2 emissions peak this year (other factors being equal), we would have a realistic chance of averting the worst impacts of climate change. But if emissions peak in 2020, global climate will stay in the danger zone for about a century. Worse yet, if emissions do not peak till 2030, we could be in the danger zone for 400 years or more.
Barring revolutionary shifts in energy use worldwide, it’s highly unlikely that global CO2 emissions will peak this year. But our results strongly emphasize that we must act within this decade to pursue cleaner energy, to ensure that the climate will be livable for our descendants. It will require massive efforts worldwide but it is doable—the means are basically there, what’s missing is the will of governments to act meaningfully . Sustained public pressure could make a huge difference in that regard .