Time and again climate Deniers parade how little they understand climate science when they claim that some “new study has proven climate change theory is wrong”. Two reasons for this, both relating to the scale and scope of climate science.
The Deniers seem to think that climate science is a three legged stool, and if they could only knock out one leg it will fall over. Wrong metaphor; it is more like an 18 wheeler. Even if they managed to puncture one tire (which they have yet to do) it would make no noticeable difference. Two, even three wouldn’t change much.
To understand why let’s have a look at part of of Buchdahl’s excellent Global Warming Student Guide. As you will see the evidence for climate change comes from thousands of studies across many disciplines. Below is the table of contents for Section 3 of the Guide.
3. Empirical Study of the Climate 3.1. Introduction
3.2. Climate Construction from Instrumental Data
3.2.1. Measurement of Climate Elements
22.214.171.124. Measurement of Temperature
126.96.36.199. Measurement of Rainfall
188.8.131.52. Measurement of Humidity
184.108.40.206. Measurement of Wind
3.2.3. Statistical Analysis of Instrumental Records
3.3. Palaeoclimate Reconstruction from Proxy Data
3.3.1. Historical Records
3.3.2. Ice Cores
220.127.116.11. Stable Isotope Analysis
18.104.22.168. Physical and Chemical Characteristics of Ice Cores
22.214.171.124. Dating Ice Cores
3.3.4. Ocean Sediments
126.96.36.199. Palaeoclimatic Reconstruction from Biogenic Material
188.8.131.52. Palaeoclimatic Reconstruction from Terrigenous Material
3.3.5. Terrestrial Sediments
184.108.40.206. Periglacial Features
220.127.116.11. Glacier Fluctuations
18.104.22.168. Lake-Level Fluctuations
3.3.6. Pollen Analysis
3.3.7. Sedimentary Rocks
To get a sense of the diversity of data, consider how we know the earth is warming. There are direct temperature measurements of course. There is also secondary evidence such as melting glaciers and ice sheets, thermal expansion of water, impacts on and changes in natural systems, long term changes in weather, and so on (see also here for examples).
For temperature measurements there are land based monitoring stations, ship based temperature monitoring, ocean bouy temperature stations, weather balloons and aircraft based measurements, and satellites of course.
These are spread across many nations all over the world, use slightly different technologies and methodologies, and monitored by hundreds of different research institutions.
Now have a look at just some of the different sources for the data. Remember that even when we are talking about exactly the same type of data it is coming from many different studies by many different scientists and research institutions. At the link given you get 5 different sources for each of land based and satellite based temperatures.
Just for fun let’s pretend that one of the less silly Denier Myths were true, that urban heat islands have made many of the land based surface temperature records useless (they haven’t). Ok, we throw those out.
Climate change science down the drain? Hardly. We still have all of the rural land based records, plus all of the other temperature records, and all of the secondary evidence.
What if another of their myths were true, that the satellite data shows cooling (it doesn’t)? Two wheels down, climate science out the window? No! There is still a lot more data supporting climate change than not.
Of course scientists would want to understand why the satellites showed this (if they did), and they would be looking at it very hard until they came up with a rational answer, but it doesn’t affect all of the other evidence, both direct and indirect.
And of course this all shows just what nonsense the Denier claim that “climate change is just based on computer models that are flawed” is. A claim that is nonsense for other reasons as well (see here and here).
What if there was a study that really undermined climate science? Something that just blew out a bunch of our metaphorical tires all at once.
In the first place it would take something pretty significant to do that, as I have discussed before. For the exercise let’s say a study that shows conclusively that temperatures over the past century correlate perfectly with changes in solar irradiance (after factoring out other influences).
No matter how reputable the researchers and how good the science may seem, this would still not result in immediately declaring climate change disproved. Even if there were only one other study from before, this would still leave us with one for, one against. “New” does not necessarily mean “better” or “more correct.”
Of course there is not just one previous study, there are many. As such scientists would look at the new study very closely and try to see if it’s findings could be repeated. If, and only if, they could find nothing wrong with the study and they were able to repeat the findings would they try to discover how all of the previous studies of solar irradiance could be wrong.
Only then might we consider tossing out the idea of anthropogenic climate change, and even so we would still be stuck trying to understand why CO2 was not having a warming effect. The impact on all of science would be huge.
The point is that any claim that “a new study” has undermined climate science is 99.9% certain to be nonsense. You don’t even have to look at it to know that.
Even if the study turns out to be flawless (extremely unlikely given the scale and scope of climate science) it will be quite a while before science confirms it’s validity.
As long as it is “one new study” you can be certain it hasn’t undermined anything. It may have raised some questions, it may have cause some doubts, and although improbable in the extreme it may even lead to toppling the current understandings of climate change entirely … but that would be in the future when the “one study” has become “many studies” confirming the new understandings.
So when you see that Denier headline “new study proves climate change theory is wrong” you know the claim is bunk. You also know just how well the person making the claim understands climate science.
UPDATE: Nov 10 2009 see also
Denier “Challenge” aka Deathwatch Update: Day 52 … still no evidence.