Climate – What do we know?

5 05 2014

Another guest post from our friend Mark Cochrane……

If you have not yet watched the Ted Talk by Gavin Schmidt below, I highly recommend that you do so.

It is often authoritatively stated that:

adaptation costs are likely to be both less than mitigation costs and manageable.

which is a wholly unsubstantiated opinion that is refuted by hundreds, if not thousands, of scientific studies as recently reported in the Working Group II – adaptation (link), and Working Group III – mitigation (link) IPCC reports that have come out this year.

However, you do not need reams of technical materials to have basic sense. The logic and wisdom of the matter was succinctly provided by Benjamin Franklin and climate change is no exception.

An ounce of prevention is worth a pound of cure.

We know that we should substantially reduce our reliance on fossil fuels, actively seek alternative energy sources, and dramatically improve the efficiency with which we utilize energy. This statement would be true even if climate change issues were not at stake. Unless you fail to believe M. King Hubbert (1956 – Peak Oil), Meadows et al (1972-present Limits to Growth), and some guy named Chris Martenson (Crash Course – review here), you cannot help but know in your gut if not your head that our economic and societal over-reliance on rapidly depleting fossil fuel resources is a recipe for disaster, regardless of the climate consequences.

But since this topic is a climate one, what about the climate issues?  Christopher Monckton’s long debunked point about earlier periods of rapid warming is worth mentioning here. The 1920-1950 period actually would be relatively low warming, the correct period at issue is 1910-1940 when there was substantial warming that was only minimally related to human activities. Even so, that period did not warm as fast as we are currently experiencing.

However, this does provide a powerful indication of why we know that human-related emissions of greenhouse gases are of critical importance in ongoing climate changes. As Gavin Schmidt shows, the models are quite skillful in simulating many of the various climate processes at work throughout the world. The contrast between the the 1910-1940 and the 1970-present periods is very illustrative because we can compare modelled results to the actual observations of what has occurred in the global climate. When we look at how the models correspond to the climate record when forced only with ‘natural forcings’ (i.e. no additional greenhouse gases), we can see that the 1910-1940 period of warming is fairly well explained, while the rapid warming that we are currently experiencing is almost completely unexplained. (See Skeptical Science for a more detailed description of pre-1940 Warming Causes and Logic).

Conversely, if we remove the ‘natural forcings’ and only include greenhouse gas increases caused by human activities (primarily fossil fuel use), we see that although humans did not have much of a hand in the 1910-1940 warming, we are certainly in the driver’s seat of change now.

Actual climate change is from the combination of natural forcing and our accumulated greenhouse gas emissions. We know that we have to kick the fossil fuel habit. While Limits to Growth, the Crash Course and other sources clearly indicate that there is going to be a serious hangover for humanity coming when, as Heinberg says, the Party’s Over, as fossil fuels become less and less available, the climate change effects are going to be handed to future generations as the unpaid bar tab of our ongoing fossil fuel binge.

Mark

“What’s the use of having developed a science well enough to make predictions if, in the end, all we’re willing to do is stand around and wait for them to come true?”
F. Sherwood Rowland

Advertisements

Actions

Information

4 responses

5 05 2014
bry

You state that the 1910-1940 warming had little human input. Surely two world wars have had to have had some effect. If that is so, it is worrying as our present emissions seem to be having a similair effect as two worldwide conflagrations!

5 05 2014
mikestasse

OK……. first, I didn’t write this, it’s a guest post by Mark Cochrane.

Secondly, WWII started in 1940, so the effect of that war had not shown up yet in that period.. what caused the ‘cooling’ DURING the war?

Your last statement is spot on…. it is worrying alright.

5 05 2014
bry

Thanks for taking the time to reply. No offence was intended. Just thoughts of the top of my head. Point taken about WWII although there had been build up to WWII eg Spanish Civil War , Japanese invasion of China etc plus in 1939 Germany & Russia both invaded Poland. I guess the cooling during the war was down to the large amount of aerosols released by fires, bombs, mass transport, atomic bombs etc. Love the site by the way. Thanks for all the effort you put into it.

6 05 2014
mikestasse

I think too that because there were still far fewer people around (pre-baby-boomers) emissions were still lower. In fact, even coal burning AGAs like the one I am currently using didn’t take off in numbers until after the post war austerity was over. Hardly anyone drove cars before 1950….. my parents didn’t get a car until a couple of years after I was born in 1952…

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s