There is a new paper (in press in the journal Geophysical Research Letters) that presents a lesson that we all should keep in mind—results based on reconstructions of climate phenomena that are based on once or twice removed “proxy” indicators, may not be as reliable as they appear (or as they are presented) to be. If this brings hockey sticks and salacious emails to mind, you are not alone.

“Proxies” are putative indicators of climate for which there are no direct measurements. Tree rings, for example, are wider when the summer is wet and not too hot. The actual “explained variance” between them and, say, annual temperature is complex to derive and not all that high. The same is true for most other types of proxies (e.g., corals, ice cores, lake sediments, stalagmites, boreholes, etc.). Therefore, the uncertainties in using proxies to “reconstruct” some aspect of the climate are typically large (certainly larger than typically portrayed) and making (robust) conclusions from such analyses becomes a bit tricky. Such problems are among the reasons that many people jumped all over Michael Mann’s infamous “hockey stick” reconstruction of climate, which claims to accurately represent annual temperatures on a year-to-year basis back some 1000 years. Lesson: be very careful with proxy climate data.

Today’s example involves wildfire occurrence in the western U.S., and the climate patterns that may influence it.

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It it’s 2007 Fourth Assessment Report (AR4), the Intergovernmental Panel on Climate Change (IPCC) investigated the character of the changes in precipitation that have been observed across the world over the past half-century or so. In doing so, they concluded:

Observed changes in intense precipitation (with geographically varying thresholds between the 90th and 99.9th percentile of daily precipitation events) for more than one half of the global land area indicate an increasing probability of intense precipitation events beyond that expected from changes in the mean for many extratropical regions (Groisman et al., 2005; Figure 3.39, bottom panel). This finding supports the disproportionate changes in the precipitation extremes described in the majority of regional studies above, in particular for the mid-latitudes since about 1950.

Here’s the graphic mentioned in the quote above:

Figure 1. Bottom panel of IPCC AR4 Figure 3.39 showing “regions where disproportionate changes in heavy and very heavy precipitation during the past decades were documented as either an increase (+) or decrease (–) compared to the change in the annual and/or seasonal precipitation” (from IPCC AR4, 2007).

The problem is, is that the methodology that the IPCC relied upon was insufficient to base such a conclusion.

Over those regions where a more appropriate methodology has been employed, contrary to IPCC proclamations, the changes in intense precipitation events have proven to be very much proportionate to the observed changes in total annual precipitation. And even though the IPCC knew that this was the case for at least one of these major land areas (the United States), they nevertheless chose to forward the mischaracterization.

Chalk up another addition to the list of IPCC errors.

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As we have covered in previous essays, global warming alarmists insist that the southwestern United States is getting drier and will get substantially drier in the future due to the buildup of greenhouse gases. They bolster their claims by results from a relatively large number of articles in the professional scientific literature and countless comments in various UN IPCC reports. Throw in pictures of declining water levels at Lake Mead, some fountains in Las Vegas and golf courses in Phoenix, and just like magic, a scary scenario is produced.

As with virtually every other element of the climate change issue, the literature produces some surprises, and the drought in the Southwest claim runs up against some interesting realities. The latest article on this subject appears in a recent issue of the Journal of Geophysical Research and once again, the results are at odds with the popular perception of increased drought in the Southwest.

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No presentation on global warming is complete without images of some major wildfire – from day one, the global warming alarmists have insisted that a warmer world will generate more wildfires thereby devastating ecosystems from sea to shining sea. It is an easy sell – higher temperatures will increase potential evapotranspiration, forests dry out, and therefore become far more susceptible to fire. Recall that the entire global warming issue became front-page news back in 1988, and 1988 was the summer Yellowstone Park and much of the western United States suffered severe forest fires. Ever since, every major fire somehow gets linked to global warming. We searched the internet for “Fires and Global Warming” and found literally thousands of websites claiming that global warming will cause more fires, fires are causing global warming, and of course, global warming leaders should be fired!

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In recognition of the recent discovery of the world’s largest beaver dam, we take a look into the activities of past beavers to see what they may be able to tell us about previous climate changes, and we speculate on the impacts that on-going climate changes may be having on the likes and dislikes of current beavers.

World’s largest beaver dam in found in Northern Alberta, Canada.

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One of the ongoing debates in the climate change world involves the popular prediction of more droughts, longer droughts, and droughts of greater intensity. The underpinnings of this prediction are easy to follow, so this is definitely a strong pillar in the climate alarmist camp. As the temperature increases, potential evapotranspiration (PET) will certainly increase. There are many equations describing the relationship between PET and temperature, and they all indeed show PET would increase should the temperature increase. The physics here is solid. So if PET increases, actual evaporation will increase in areas with even a small amount of soil moisture, and in the absence of some compensating increase in rainfall, soil moisture will be depleted. The combination of increasing temperatures and decreasing precipitation should all but guarantee the place will become drier thereby yielding the increase in drought duration, intensity, and frequency. There is always a drought somewhere on the planet to point to as evidence that this is really happening, will likely get worse in the future, and all the rest. We’ve all heard it a million times … “If we don’t act know, ______ will happen” (fill in the blank, but today, we will focus on droughts).

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If you really want to hit a home run with a global warming story, manage to link climate change to the beloved rainforest of the Amazon. The rainforest there is considered by many to be the “lungs of the planet,” the rainforest surely contains a cure for any ailment imaginable, all species in the place are critical to the existence of life on the Earth, and the people of the Amazon are surely the most knowledgeable group on the planet regarding how to care for Mother Earth.

The global warming alarmists have taken full advantage of the Amazon and they are very quick to suggest that the Amazon ecosystem is extremely sensitive to climate change. Furthermore, not only can climate change impact the Amazon, but global climate itself is strongly linked to the state of the Amazon rainforest.

But, as usual, there is more to this story than meets to eye (or, rather, the press).

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We are sure you have heard that global warming is causing more frequent and intense droughts throughout the world. Right? The claim is easy to make – higher temperatures increase evaporation rates, soil moisture is depleted, and drought conditions result. Indeed the Technical Summary of the most recent IPCC assessment includes “More intense and longer droughts have been observed over wider areas, particularly in the tropics and subtropics since the 1970s. While there are many different measures of drought, many studies use precipitation changes together with temperature. Increased drying due to higher temperatures and decreased land precipitation have contributed to these changes”. Further, they write “Although precipitation has increased in many areas of the globe, the area under drought has also increased. Drought duration and intensity has also increased. While regional droughts have occurred in the past, the widespread spatial extent of current droughts is broadly consistent with expected changes in the hydrologic cycle under warming. Water vapour increases with increasing global temperature, due to increased evaporation where surface moisture is available, and this tends to increase precipitation. However, increased continental temperatures are expected to lead to greater evaporation and drying, which is particularly important in dry regions where surface moisture is limited.” The bottom line in the table below from the IPCC’s Technical Summary leaves little doubt that the IPCC thinks that droughts have become more frequent, they have been caused in some part by humans, and they will become more frequent in the decades to come.

A major article on global-scale drought has appeared recently in the Journal of Climate by drought experts from Princeton University and the University of Washington; the work was supported by the U.S. Department of Energy the National Oceanic and Atmospheric Administration. We saw an interesting sentence in their abstract as Sheffield et al. wrote “Globally, the mid-1950s showed the highest drought activity and the mid-1970s to mid-1980s the lowest activity.” That does not seem consistent with the story coming from the IPCC.

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Of the many pillars that support the alarmist view of global warming is that droughts will increase in many parts of the world. This prediction is fairly straightforward, for if temperatures increase, potential evapotranspiration (ETo) should increase as well. If precipitation stays the same in the future and ETo increases with higher temperatures, the area would see a reduction in soil moisture and a trend toward drought. Of course should precipitation be reduced while ETo rates increase, the trend toward drought could be severe. In the ultimate alarmist view, ETo increase and extreme precipitation increases, and the area would then see an increase in both floods and droughts. We have heard it all before and we have covered these topics in many essays, but the beat goes on and on.

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Who could ever forget one of the opening scenes in The Day After Tomorrow when hailstones the size of basketballs were crashing into Tokyo causing death and destruction. Obviously, the greenhouse alarmists cannot wait to claim that severe storms will increase in frequency and intensity in the future, and nothing drives home the point like a city being punished by killer hail stones.

Amazingly, a search of “Global Warming and Hail” produces over one million hits, although some include the word “hail” as a word to “summon” or “call” for some action and have nothing to do with ice falling from the sky. Nonetheless, there is no end of material with titles about Nebraska towns using snowplows in summer to clear hail, crops being damaged by unusual hail events, and on and on. One of our favorites is “Latest Global Warming Worry: Megacryometeors” – use the word “megacryometeors” at the next greenie cocktail party and you will definitely win the award for outstanding global warming vocabulary!

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