Why environmentalists may be to BLAME for recent warming

The Register reports on a study by NASA scientist Dr. Drew Shindell suggesting a strong correlation between the fight against acid rain in the 1970s and the abrupt reversal in northern hemisphere temperature trends.

Dr Drew Shindell of NASA's Goddard Institute of Space Studies has led a new study which indicates that much of the general upward trend in temperatures since the 1970s - particularly in the Arctic - may have resulted from changes in levels of solid "aerosol" particles in the atmosphere, rather than elevated CO2. Arctic temperatures are of particular concern to those worried about the effects of global warming, as a melting of the ice cap could lead to disastrous rises in sea level - of a sort which might burst the Thames Barrier and flood London, for instance.

Shindell's research indicates that, ironically, much of the rise in polar temperature seen over the last few decades may have resulted from US and European restrictions on sulphur emissions. According to NASA:

Sulfates, which come primarily from the burning of coal and oil, scatter incoming solar radiation and have a net cooling effect on climate. Over the past three decades, the United States and European countries have passed a series of laws that have reduced sulfate emissions by 50 percent. While improving air quality and aiding public health, the result has been less atmospheric cooling from sulfates.

So, the reduction in sulfate pollution meant the elimination of a significant counterbalance to increasing soot pollution.

Am I advocating the wholesale repeal of sulfate emission restrictions? Not really -- in fact, I'm not ready to concede any human influence in the climate cycle (hence the blog name). I do note, though, that those who believe in consequential human influence on climate must acknowledge that attempts to "fix" what is allegedly broken can often have unforeseen effects.

Winter 2007-8: It's all in how you look at it

The National Oceanic and Atmospheric Administration presents a straightforward acknowledgment that this winter has bucked the trend of recent years:

NOAA: Coolest Winter Since 2001 for U.S., Globe

The average temperature across both the contiguous U.S. and the globe during climatological winter (December 2007-February 2008) was the coolest since 2001, according to scientists at NOAA’s National Climatic Data Center in Asheville, N.C. In terms of winter precipitation, Pacific storms, bringing heavy precipitation to large parts of the West, produced high snowpack that will provide welcome runoff this spring.

The Associated Press, looking at the same press release, ignored NOAA's summary and zeroed in on the one thing that matters most to the CoGW:

Winter Has Been Warmer Than Average

WASHINGTON (AP) -- Winter storms and snow notwithstanding, this winter was still warmer than average worldwide, the government reported Thursday.

A modest request to those who believe in anthropogenic "climate change"

Despite the name of this blog, some time ago many in the CoGW abandoned the exclusive use of the term "global warming" to describe current climate trends. "Climate change" is the preferred term now, since many weather events in recent years do not appear to fit the perception of what we would see on an unnaturally warming planet.

I will continue to use "Anthropogenic Global Warming" (AGW) to describe this ideology. Although atmospheric CO₂ concentrations continue to increase, global temperatures have more or less plateaued in the past decade. Since the plateau occurred at a warm average temperature, we've been treated to innumerable accounts of the fact that recent years have been among the warmest in recent history. So, despite the use of the term "climate change", it's clear that proponents are invested in creating the public perception that the earth is continuing to warm (and that such warming will soon accelerate out of control).

Climate change really is a term of art, because it allows CoGW adherents to insist that all weather -- wet or dry, hot or cold -- validates the AGW orthodoxy.

Floods in China: check. Drought in China: check. More hurricanes: check. Fewer hurricanes: check. Summer ice melt in the Arctic: check. Winter refreezing of Arctic ice that exceeds that which originally melted: check. Collapse of the West Antarctica Ice Shelf: check. Net increase in Antarctic ice: check. Record warm winter in 2006-2007: check. Record cold winter in 2007-2008: check.

And so on.

This leads me to ask a question of those of you who believe that human activity is negatively and catastrophically impacting the earth's climate:

Is the anthropogenic climate change hypothesis falsifiable?

I am asking this within the context of the scientific method. Integrity demands that a scientist, when proposing a hypothesis, list the conditions whereby the hypothesis would fall apart:

We believe that this hypothesis sufficiently describes the reality we are studying, but if anybody can demonstrate any of conditions a, b, c, d or e, our hypothesis is fatally compromised and it's back to the drawing board.

So, AGW folks: can you name any condition (series of weather events, temperature trends, etc.) that would make you doubt the current orthodoxy, or are we witnessing the most bulletproof hypothesis ever?

UPDATE: After a quick Google search, I was pleased to discover that this question has already occurred to minds much greater than mine. As I composed this post earlier today, I had the folks at RealClimate in mind (among others). It turns out that Roger Pielke, Jr. tossed the following rhetorical grenade into the midst of a RealClimate discussion about how awfully cold Antarctica is right now:

There are a vast number of behaviors of the climate system that are consistent with climate model predictions, along the lines of your conclusion: “A cold Antarctica and Southern Ocean do not contradict our models of global warming.”

I have asked many times and never received an answer here: What behavior of the climate system would contradict models of global warming? Specifically what behavior of what variables over what time scales? This should be a simple question to answer.

Thanks!

The ensuing debate is pretty interesting.

Pielke followed up on the question in his own blog. The debate is pretty lively in the comment section over there as well.

(Found via: Seeker Blog)

One sense in which global warming IS man-made

John Brignell of Numberwatch:

When you are trying to troubleshoot an instrumentation system (whether it is in examining a PhD thesis or facing a major industrial crisis) there are, self-evidently, two vital areas you need to address:

1. The physical process of data acquisition
2. The computational process of Data handling

The central problem with data acquisition, now that data conversion is largely standardised through advances in electronics, is the housing and siting of sensors. Sometimes the problems are glaring, such as caking with mud or salt, but often they are more subtle and veiled. Particularly difficult are cases where instrumentation interacts with nearby systems (see appendix below for an example where an expensive court case was averted).

Data handling is an even greater problem, especially when “intuitive” or obscurely argued methods are implemented. Even if we discount the possibility of deliberate fraud, the power of the human subconscious to influence outcomes is a known but difficult to quantify hazard, especially in computer programs.

In considering data handling for climate monitoring in these terms, we now have the advantage of new information on siting and a description, though not a perspicuous one, of alterations made to original data.

We have long known that there have been examples of badly sited monitoring stations. The late John Daly showed seven years ago an example of bad siting, while, incidentally, raising the question of whether the surface record was as reliable as we were led to believe and proposing improvements of methodology. Daly’s analysis has not only stood the test of time, but has been vindicated by recent developments. The satellite record continues to show little or no change while the surface record shows what s alleged to be a continued rising trend.

Brignell shows two graphs displaying the difference between satellite and surface measurements in recent decades, and then goes on:

This is what John Daly wrote seven years ago about surface stations:

The only way surface data can be used with any confidence is to exclude all town/city and airport data - no exceptions. Only rural sites should be used, and by `rural’ is meant strictly `greenfields’ sites where there is no urbanisation of any kind near the instrument. Even when greenfields stations are used, those which are technically supervised (eg. managed by scientists, marine authorities, the military etc.) should be treated with greater credibility than those from sheep stations, post offices and remote motels.

As it turns out, the temperatures recorded by urbanized weather stations skew the surface averages enough to account for most of the claimed global temperature increase of the past century.

Brignell also demonstrates faults in the processing of the data.

So, in a sense, global warming really is man-made -- through man's faulty collection and processing of the critical data.


UPDATE: The American Association of State Climatologists, while apparently unconcerned about the physical location of weather stations, petitioned Congress in March to address the antiquated equipment and obsolete data collection techniques that plague America's weather station network.

(Thanks to JunkScience.com for the links)