We’re not entirely sure, it turns out. For a long time now, climatologists have believed that the contrails–those white vapor trails left by airplanes you see criss-crossing the sky–had a net warming effect.They believed that the amount of heat the makeshift clouds trapped down towards the Earth’s surface was greater than the amount of warming they prevented by blocking out the sun’s rays. But one researcher looked at data collected in the three days after September 11th, when the skies above the U.S. were empty, and found that the average high temperatures during those days were higher than normal.The only problem is that those three days were also abnormally clear and cloud-free, so it might be natural variation at play. That there is some warming or cooling impact is certain; we need some more research to determine which it is.Image courtesy of Wikimedia (cc) and NASAThis post originally appeared on www.refresheverything.com, as part of GOOD’s collaboration with the Pepsi Refresh Project, a catalyst for world-changing ideas. Find out more about the Refresh campaign, or to submit your own idea today.
Tags
advertisement
More for You
-
14 images of badass women who destroyed stereotypes and inspired future generations
These trailblazers redefined what a woman could be.
Throughout history, women have stood up and fought to break down barriers imposed on them from stereotypes and societal expectations. The trailblazers in these photos made history and redefined what a woman could be. In doing so, they paved the way for future generations to stand up and continue to fight for equality.
-
Why mass shootings spawn conspiracy theories
Mass shootings and conspiracy theories have a long history.
While conspiracy theories are not limited to any topic, there is one type of event that seems particularly likely to spark them: mass shootings, typically defined as attacks in which a shooter kills at least four other people.
When one person kills many others in a single incident, particularly when it seems random, people naturally seek out answers for why the tragedy happened. After all, if a mass shooting is random, anyone can be a target.
Pointing to some nefarious plan by a powerful group – such as the government – can be more comforting than the idea that the attack was the result of a disturbed or mentally ill individual who obtained a firearm legally.
advertisement

