Global warming is a contentious subject, and the climate models used by the Intergovernmental Panel on Climate Change (IPCC) to predict future changes are, by their very nature, based on the best estimates according to current scientific understanding. One of the essential factors considered by these models is the role of clouds, as the cloudier our skies – or the whiter the clouds – the more sunlight is reflected back into space, which has a cooling effect on our planet. Up until now, scientists had believed that the aerosols pumped into the atmosphere had caused clouds to be much whiter than in preindustrial times, having a cooling effect and masking some of the impacts of anthropogenic activity. But new research, published concurrently in three separate papers, suggests that clouds may have changed little, with implications for our understanding of global warming. "It's a complicated issue," says Neil Donahue of Carnegie Mellon University, coauthor on two of the papers, in a phone interview with The Christian Science Monitor, "and this work is dealing with uncertainty, dealing with the limits of our understanding, rather than turning our understanding upside down."
Most computer simulations of climate change are underestimating by at least one degree how warm the world will get this century, a new study suggests. It all comes down to clouds and how much heat they are trapping. According to the study published Thursday in the journal Science, computer model simulations say there is more ice and less liquid water in clouds than a decade of satellite observations show. Most computer simulations of climate change are underestimating by at least one degree how warm the world will get this century, a new study suggests. In 2013, the Intergovernmental Panel on Climate Change (IPCC) estimated climate sensitivity to be within a range of 2 to 4.7 degrees Celsius.
This story was originally published by Wired and is reproduced here as part of the Climate Desk collaboration. If one is the loneliest number, two is the most terrifying. Humanity must not pass a rise of 2 degrees Celsius in global temperature from pre-industrial levels, so says the Paris climate agreement. The frustrating bit about studying climate change is the inherent uncertainty of it all. Predicting where it's going is a matter of mashing up thousands of variables in massive, confounding systems.
To some, clouds resemble bunnies. To others, they can look like squished flowers. When scientists used NASA data to peer into clouds, what they saw resembled a hazard sign warning of a fast-deteriorating climate ahead. Analysis of the first seven years of data from a NASA cloud-monitoring mission suggests clouds are doing less to slow the warming of the planet than previously thought, and that temperatures may rise faster than expected as greenhouse gas pollution worsens -- perhaps 25% faster. SEE ALSO: The U.S. is experiencing its third warmest year-to-date Clouds can play an important role in slowing global warming by reflecting energy back into space.