Sunday, May 17, 2015

Blame the Heat on Global Warming

I can personally tell you there are more really hot days today than there were even a few decades ago. So can lots of other people. But, that is merely anecdotal evidence and we need something more rigorous than that. Of course, we have exactly that in the data, showing global warming has been getting worse since the 1970s. Nine of the ten hottest years have occurred since 2000. Last year was the hottest ever recorded and this year is already breaking last year's records. So, we have the hard data.

But, what does that mean? How does that affect the average person?

Well, research on this very question has shown that three out of four very hot days can be blamed on anthropogenic global warming. As things get worse during this century, that percentage will increase to 95%. Rain is a different matter. It is estimated we are responsible for only 18% of the very heavy downpours and this will increase to 39% by mid-century.

The researchers reached this conclusion by examining the hottest .1% of days and found they occurred only once every three years in a world without CO2 emissions. But, when they added manmade emissions into the equation, they found there were four of these very hot days every three years. If they continued to increase the amount of CO2 in the atmosphere to levels expected by the end of the century, they got 26 days every three years. That's something to look forward to - twenty-six times as many very hot days.

Equipped with figures like this, we can now make very strong arguments about the damage being done due to climate change. If 100,000 people die this year due to climate extremes, we can make a good estimate of how many would still be alive if not for fossil fuel emissions. We can discuss the dollar amount of damage done and present that as part of the argument to form public policy.

So, the next time you find it to be really hot, there's a 75% chance you can thank fossil fuel emissions for it.


  1. Yet isn't it quite recently that climate scientists have felt comfortable in specifically blaming certain extreme weather events at least partially on global warming? Even so, it's probably logical to assume that they must have been pretty darn convinced to make such an observation, seeing how careful the scientific community is when it comes to having all their its ducks in a row before reaching any definite conclusions at all.

  2. That is one of the criticisms I have leveled against the community. We are, by nature and training, a group of people that will analyze the data to death before boldly predicting what happened ten years ago. It's just part of the job.