SMART NEWS

On a Warmer Planet, Fewer Clouds Form, And Temperatures Rise Further

Scientists use words such as “catastrophic,” “impossible” and “profound” to describe what life on the planet would be like under 4-degree-warmer conditions

Rachel Nuwer

January 2, 2014

The computer models that scientists use to predict the impacts of climate change are very good—but they're not perfect. One blind spot was clouds—scientists could not fully forecast climate change’s impact on cloud cover, which in turn affects temperature. But the newest climate predictions, published in Nature, do take clouds into account, and the results don't bode well for the planet's future.

According to the researchers, global temperatures will rise a minimum of 4 degrees Celsius over the next 100 years, firmly placing those predictions on the high end of what researchers previously suspected might occur. In the Guardian, scientists use words like "catastrophic," "impossible" and "profound" to describe what life on the planet would be like under 4-degree-warmer conditions.

The Guardian explains clouds' role in the warming:

The research indicates that fewer clouds form as the planet warms, meaning less sunlight is reflected back into space, driving temperatures up further still.

The key was to ensure that the way clouds form in the real world was accurately represented in computer climate models, which are the only tool researchers have to predict future temperatures. When water evaporates from the oceans, the vapour can rise over nine miles to form rain clouds that reflect sunlight; or it may rise just a few miles and drift back down without forming clouds. In reality, both processes occur, and climate models encompassing this complexity predicted significantly higher future temperatures than those only including the nine-mile-high clouds.

Past research has predicted a rise in temperature varying between 1.5 to 5 degrees Celsius; the new paper, however, shaves off some of that uncertainty and bumps that warming up to 3 to 5 degrees Celsius, the Guardian says.