Cato: Climate vs. Climate Change

There seems to be a fundamental misunderstanding in the difference between climate and climate change.

This is on very public display in the president’s recently unveiled Climate Action Plan, which details a series of executive actions designed to reduce greenhouse gas emissions in an attempt to control the future course of the climate.

In justifying the need for these actions, and why he doesn’t have time to wait for Congress to act, the president points to numerous recent examples of extreme weather disasters while linking weather extremes to climate change brought about by anthropogenic greenhouse gases emissions.

In doing so, he goes awry of the best science.

Here’s why.

The natural climate of the U.S. includes all manner of extreme weather events—hurricanes, tornadoes, droughts, floods, heatwaves, cold outbreaks, derechos, and virtually every other type of bad weather you can dream up.

This is true now, just as it was 100 years ago, before greenhouse gases were being emitted to the atmosphere in large quantities from human activities—primarily the burning of fossil fuels to produce energy.

Human-caused climate change is an incremental pressure to slightly alter the character of weather events, for example, their frequency and/or magnitude. This includes weather events both extreme and otherwise. The nature of this alteration, if it occurs at all, is scientifically uncertain for most types of weather.

In other words, every time there is some sort of weather “disaster” you don’t need to invoke climate change to explain it. A simple climate explanation will usually suffice. In fact, bringing climate change into the explanation usually runs afoul of our current scientific understanding. It is as easy to argue that climate change mitigates (or even averts) weather disasters as it is to argue that it augments them.

But folks pushing for greenhouse gas regulations don’t often let the facts get in the way.

This includes the president, as well as many of his federal advisors.

For example, Roger Pielke Jr., a leader in the field of weather disaster trends, tweeted this about the president’s speech on Tuesday:

@RogerPielkeJr “Will be interesting to see if anyone on the side of climate action will care that Obama’s plan begins w/ false claims about disaster trends”

And in our recent review of the draft version of the government’s latest National Assessment report, we point out the pervasive confusion between climate and climate change within the report. For example, regarding impacts on the transportation sector, we note:

It is not climate change, but the vagaries of the climate itself that have the greatest impact on U.S. transportation. Climate change, to the degree that it is detectable and identifiable, contributes a mix of impacts, some positive and some negative, and the net impact has never been reliably quantified or monetized.

The impacts of climate and climate change are confused and thus used interchangeably, however, such usage is incorrect and misleading.

Perhaps the biggest reason why it is easy to confuse climate and climate change, is that it appears that the weather is getting worse—that is, there are more, and more costly, extreme weather events. The climate must be changing to make this happen, right?

Wrong.

What is changing, besides increased media (both mainstream and social) coverage, is that there are more people, with more (valuable) stuff, in harm’s way.

So, even in a constant climate, the frequency and magnitude of extreme weather events—such as those included in the government’s annual list of “Billion Dollar Weather/Climate Disasters”—will increase.

Yet the president points to this increase and links it to human-caused climate change.

Read more at http://www.cato.org/blog/climate-vs-climate-change