Getting model-data comparison right

One of the favorite criticisms harped on by deniers is that global temperature isn’t rising as fast as computer models have predicted. So far, comparisons have shown that observed temperature is on the low end, even skirting the significantly low end, of model results. They generally use this to imply, or say outright, that not only are models “wrong wrong wrong” but the whole of climate science is “wrong wrong wrong.”

Of course it might be a valid criticism of the models, but not of global warming theory which most decidedly does not depend on complex computer models. The models are just our best way of forecasting what the future will bring; they aren’t necessary to understand, or confirm by many observations (not just temperature data), the physics behind man-made climate change.

Where most of us live (with apologies to southern-hemisphere readers)

Almost all of us live on land, not the ocean. And, most of us live in the northern hemisphere, not the southern. For the benefit of most of us, let’s take a closer look at how temperature has changed, in the northern hemisphere, on land.

Quick note to regular readers

We’ve contacted Paypal, they tell us that the problem with donations has been a glitch on their end. They also say that sometime tomorrow or the next, it should be working OK.

I’ll also mention that, although I often post about new scientific results and mathematical analyses, often quite technical, I also feel the need to post about what’s happening right now, and in simple terms. Many of you are quite knowledgeable and sophisticated, but I need to write stuff for the more typical lay reader as well. So, my next post will be a simple exposition of recent temperature in the northern hemisphere, on land, but (I hope!) will not be very technical.

Mad not a scientists

It speaks for itself.

Hansen et al.

A new paper by Hansen et al., Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 °C global warming is highly dangerous is currently under review at the journal Atmospheric Chemistry and Physics Discussion.

The paper explores the possibility of, and consequences of, much more rapid melting of earth’s great ice sheets in Greenland and Antarctica. It surveys evidence from the previous interglacial (the Eemian, about a hundred thousand years ago) of rapid fluctuations in sea level, its potential impact on the ocean’s overturning circulation, and of extreme storms as a consequence. It also reports the results of model simulations which include more, and rapidly increasing, injection of fresh water in regions of the ocean (around Antarctica and the north Atlantic) near the great ice sheets.

Thank You

To all the readers who make this blog worth writing: Thank you.

Another Republican Politician

Dana Rohrabacher is currently serving as Vice Chairman of the House Committe on Science, Space and Technology. As John Stewart so pointedly asked, “How far back to the elementary school core curriculum do we have to go to get someone on the House Committe on Science, Space, and Technology caught up?”

In Dana Rorhabacher’s case, I doubt we could ever get elementary enough.

Republican politicians at work

I suggest you begin at the 3-minute mark.

Five Signs of Denial

CNN has published an important article by John Cook outlining The 5 telltale techniques of climate change denial.

NASA and NOAA

We now have data for global temperature at earth’s surface (which is where we live) through June of this year, from both NASA and NOAA. Graphs are a lot less messy if we convert monthly data to yearly, simply by computing annual averages. This year (2015) isn’t complete yet, but I’ll plot the 2015-so-far averages anyway, to give you an idea of how the year is shaping up compared to previous years. I’ll also put them on the same baseline, more easily to compare the two. Without further ado, here’s the result: