Guest post: The science of climate change is important
Originally a comment by Coel on Brought to you by.
Since climate change matters and since the science of climate change is important:
Whenever there is a cold snap or a snow storm some will inevitably quip “so much for global warming” and use one weather event as an excuse to ignore the settled opinion about climate change. They are very wrong to do so.
It is equally wrong to point to a drought event, a drought-caused fire, or indeed a hurricane, and suggest that it is due to climate change, or even to suggest that climate change has made those events much more likely. We don’t know enough to know that. After all, California is a semi-desert and prolonged droughts are normal for California (Bristlecone pines show this over eons).
Now, climate models do suggest that the likelihood of a severe Californian drought should have increased, owing to AGW, but only by about 30 percent or so. And this is a really hard thing to model. At this level of prediction, such models are not really verified by data. The model uncertainties are about at the same level as the predicted effects.
Such models also predict that hurricane frequency and intensity should be increasing (global warming => more energy in the system). The problem is that the data don’t show this. So that means that there is a lot that we don’t understand about the formation of hurricanes (which is not a surprise, we know that we don’t know).
So is climate change increasing drought likelihood in California? Well, maybe, but we really don’t know that. We don’t have a good-enough record of data to answer that directly, and we need to bear in mind the limitations of the models; it is wrong to overclaim.
Note that uncertainties in whether climate change is increasing drought likelihood in California is a very different matter from whether climate change is happening globally (that is settled, yes it is). That’s because it is way easier to model the global response to things like CO2 and the global climate as a whole than it is to then reliably predict local fluctuations in one small part of the system (such as Californian droughts).
As I said, understanding the science of climate change does matter and it’s important to avoid overclaiming (and hence: “this drought is caused by climate change” is as dubious as “this cold snap refutes global warming”).
Thanks Coel, a very agreeable post. Given that the science on this is inexact, it certainly would be foolish to claim that any local event is caused solely by human manipulation. Given that, the worldwide evidence is damning. It can’t be claimed that human activity has had no effect at all, and that ‘Mother Nature’ will heal all. Look at the waste that’s been dumped in the ocean and the effects of that which are only now coming to light. Are we ruining the planet? Well sure we are, but it’s not happening as fast as the alarmists would have us believe, but by the same token, there is significant measurable damage. I remember Rush Limbaugh, back in the day, claiming that it’s all cyclical, and the effects of human enterprise, such as pumping as much fossil fuel out of the Earth and burning it have only a marginal effect, and that ‘Mother Earth will compensate, and we have nothing to worry about. It will all heal. Boy was he wrong.
We, as humans, are capable of having an enormous nuclear catastrophe that would cause immense ecological damage in very short order. That’s what we’re capable of. Burning as much fossil fuel as possible will cause just as much ecological damage — it’s just a slower death.
I would agree with all of the above, but I would add that our planet is the most complex totality that we know about in the entire Universe, consisting as it does of lithosphere, hydrospherre, cryosphere, atmosphere and biosphere, each with its own collection of sub-components.. And absorption of extra incoming energy from the Sun can only increase the internal energy of the whole shebang.
The key indicator is not temperature so much as sea-level rise, and the best source on that that I know of is the Sea-level Group at the University of Colorado. (https://sealevel.colorado.edu/ )
But the Earth is still here, and has undoubtedly been through far worse and survived. It could be that the Earth’s ever-changing albedo, or reflectivity, is the key. As the world’s average ocean temperature rises, it will increase the humidity of the atmosphere, leading to increasing cloud cover, thunderstorms and other such events, and moving towards a permanent obscuring of the Sun and stars for surface-dwellers, and an endless series of totally overcast days.
To achieve this, all we need to do is pass some critical tipping point, which we may or may not know about.