Global Warming Canards: Recent Cool Weather Disproves Global Warming

Where I live ... Houston, Texas ... it has been colder than normal so far this year. That is probably true for those of you reading this as well, since most of North America and Europe have been in the midst of a cold wave -- although I understand that Asia and Alaska are unusually warm. Our global warming denialist, chillbill thinks the recent cool weather disproves global warming. To make matters even more impressive, this past year 2008 was the coldest of the decade. Many global warming denialist have this canard as a central point in their denial of global warming science, including apparently chillbill (he includes versions of it in his comments here, here, here, here, here, and here).

Here are some graphs that global warming denialists use as evidence of this claim.

Figure 1

Figure 2

Figure 3

From this global warming denialists would like you to conclude:

From Figure 1: Global temperatures have remained essentially the same since 1998.

From Figure 2: Present global temperatures are failing to be what the IPCC predicted them to be.

From Figure 3: Global temperatures have fallen a little bit since 1998 while CO₂ levels have risen.

They expect you to conclude that even though the figures are inconsistent with each other. Figure 1 shows no decernible rise or fall in temperature. Figure 2 shows an overall rise in temperature with a drop at the end. Figure 3 purports to show a slight downward deflection in the temperature graph. The problem here is that data can be manipulated, and the way one manipulates the data reflects back to credibility.

The idea that the recent cold weather disproves global warming is ludicrous. I find it interesting that one of the canards used by global warming denialists is that it takes hundreds of years before we can reliably assess climate change ... yet here when one can make a graph to suit their global warming denialism, they claim that cooling over the past year disproves global warming. That statement alone should give you an idea of what the problem is with their data. Before I present the data that overwhelmingly suggests that global warming is going on stronger than ever despite 2008 being the coldest year of the decade, let's take a closer look at their data.

WEATHER is what the environmental conditions are outside your house at the moment. It is hard to predict because there are a lot of short-term fluctuations. In other words, weather is not determined by atmospheric greenhouse gas concentrations alone. There are other natural things that affect the weather. For instance, during El Nino years the global weather will be warmer than usual. During La Nina years global weather will be cooler than usual. Other than a possible effect of global warming making El Nino years more common (which to my knowledge has NOT been demonstrated to any level of certainty) this effect will be independent of atmospheric greenhouse gas concentrations.

CLIMATE is weather averaged over a time interval. The time interval is determined by the question one wants to ask and the quality of data one can obtain. We have two main sources of determining the present global temperatures. They are (1) a network of meteorological sites throughout the world that report their local temperatures, and (2) on-going satellite measurements. In general the quality of the data is excellent. As for the question of how greenhouse gas emissions are affecting our present climate, global warming science generally use a ten-year average (the five years preceeding the end of that year and the next five years after it).

If we look at figure 1 again we see that it spans the years 1998 to 2008. That is a decade, thus on the climate scale used by global warming scientists this resolves down into a single data point. No one can make a forecast from a single data point. But to make matters even worse, the data is plotted as MONTHLY averages. This short time scale will ensure a great deal of variablity which should be expected to obscure any trend line. What this graph ACTUALLY shows is the good correspondence between satellite recordings and ground-based readings. It is not appropriate to determine climate change.

Figure 2 is a montage. It is a graph of yearly global temperatures covering the years 1990 to 2007. Pasted onto the end is the global average for the first half of 2008 and a separate paste of the prediction of what global temperatures will be based on several IPCC scenarios. This graph was produced by well-known global warming denialist John Christy. It purports to show that the IPCC projections are wrong. But does it?

What it shows is that overall since 1990 there has been a rise in global temperatures. No smoothing has been done to the graph so it is difficult to determine how steep the rise is. It also shows part of 2008 which was a La Nina year (indeed at the time of this writing ... January 2009 ... we are still in the La Nina). Is that anomaly enough to cast doubt on the IPCC projections. Of course not! The IPCC is a climate projection not a weather projection. What will the weather be in an El Nino year?

Figure 3 suffers from the same problem as figure 1. It boils down to a single data point when converted from weather data to climate data. It is also misleading in that it starts at 1998, an El Nino year which is expected to be a warmer than usual year (indeed globally 1998 was the warmest year on record ... almost equaled by 2007). There are multiple data points per year which will again ensure a great deal of variability on the map obscuring any trends.

Thus, this data is presented in a manner that ensures a misleading picture. That is why global warming scientists happily go on with their business of determining reliable data and generally dismiss these claims by global warming denialists. But what is the real story?

Figure 4

This graph shows temperatures taken over the past 128 years. The red line is the climate line ... averaged temperatures. Note how ever since 1970 there has been an sharp rise, and it is unabated now. Within the yearly temperatures there have always been and there will always be years in which the temperature is cooler than the immediately previous years. This is "noise" in the data and is caused by things like El Nino's and La Nina's. Notice how averaging smooths out the noise. The upward peak is still continuing despite the temperature for 2008 being cooler. But there is more ...

While it is true that 2008 is the coolest year of the decade ... or if you want to be even more misleading -- the century or even the millenium ... it is still the 10^th WARMEST YEAR ON RECORD. That means that 2000, 2001, 2002, 2003, 2004, 2005, 2006, and 2007 were even warmer. Since 1998 was the warmest year on record that makes the 9 years of this decade the next 9 warmest years since temperature measurments have been made. The warmest decade ever was the 1990's it was 0.14^o warmer on average than the 1980's. The 2000's are on pace to be 0.22^o warmer than the 1990's. It looks like global warming denialist are even more wrong. Not only is there no real evidence that global warming is reversing, there is evidence that it is accelerating.

Chillbill asked me

Do you dispute any of these datum ... ?
1) Global temperatures have declined.
2) Sea Ice has increased.
3) CO2 emissions have exceeded projections (at least until the sudden economic contraction in Oct '08).

With respect to ANYTHING MEANINGFUL in regard to whether or not global warming is real, YES!!! I do deny that global temperatures have declined. In a future blog I will address the sea ice problem ... but as a forerunner -- the answer will be that any perceived increase in sea ice is just as misleading as any perceived decrease in global temperatures. As for CO₂ emissions exceeding projections, I'll give a qualified "Agree" answer. Climate models are based on physics not ESP. The biggest variable is what will be the response of humanity to the problem. Will we curb CO₂ emissions or not? Will we develop future technologies to handle the problem? Different models use different projections. So far we are proceeding along worst case scenarios in which CO₂ emission continue to increase.

Up next, GLOBAL WARMING CANARDS: URBAN HEAT ISLANDS