Hurricanes and global warming – still no connection

Dr. Roger Pielke Jr. sends word via email of a review of his new paper on ClimateWire, plus notes that Joe Romm “blows a gasket” about it.

That’s clear evidence that this paper is effective in refuting one of the most oft repeated climate hypes since Al Gore stood in front of a photo of Hurricane Katrina during his movie An Inconvenient Truth and said:

Now I’m going to show you, recently released, the actual ocean temperature. Of course when the oceans get warmer, that causes stronger storms

Well, no not really, the real world data says otherwise. Dr. Ryan Maue, WUWT contributor and the keeper of the Florida State University dataset on Accumlated Cyclone Energy, has this to say:

2010 is in the books: Global Tropical Cyclone Accumulated Cyclone Energy [ACE] remains lowest in at least three decades, and expected to decrease even further… For the calendar year 2010, a total of 46 tropical cyclones of tropical storm force developed in the Northern Hemisphere, the fewest since 1977.

For the calendar-year 2010, there were 66-tropical cyclones globally, the fewest in the reliable record (since 1970)!

And here’s the data plotted up through 2010, the “Hottest Year Ever”, as people like Joe are fond of saying. NASA GISS said we just finished the “warmest decade on record” in 2009, ACE is at a 30 year low in 2010

2009 was low by ACE too, one of the quietest years on record, and that hurricane season was in the middle of an El Nino, with lots of warm SST’s Pacific:

And, the North Atlantic was warmer than past years too:

There is simply is no connection between hurricanes and supposed global warming/AGW driven sea surface temperature increases, and now we have another peer reviewed paper saying there’s no signal showing a connection between hurricane damage losses and AGW. Of course they leave the door open for proving it in the future, but for the here and now, there’s no signal or connection to be made.

But don’t take my word for it, don’t take Dr. Roger Pielke’s Jr’s word for it. Have a look at these links first, then read what Dr. Pielke and his co-authors have to say. A few links:

WMO: “. . . we cannot at this time conclusively identify anthropogenic signals in past tropical cyclone data.”

– that’s the World Meteorological Organization (Knutson et al.) saying this.

Inconvenient hurricane facts

– Dr. Adam Lea, of University College London

Global Tropical Cyclone activity is at 33-year lows

Global Warming = more hurricanes | Still not happening

NOAA: More tropical storms counted due to better observational tools, wider reporting. Greenhouse warming not involved.

Increased hurricanes to global warming link: blown away

NOAA: Hurricane frequency and global warming NOT the cause of increased destruction

And then there’s this, using National Hurricane Center Data:

Yes, the lack of hurricanes during our “hottest years ever” is so bad, that Al Gore had to Photoshop them into his latest book cover:

2009 Al Gore’s Our Choice: Photoshopping Hurricanes 

Ryan Maue:  A year ago, I walked into a Tallahassee Borders and snapped an IPhone photo (that’s my thumb) of Al Gore’s new book cover and marveled at the locations of hurricanes in a globally warmed future.  The book was released at the tail end of the 2009 Atlantic hurricane season, which uncorked one of the quietest years on record.  With Copenhagen, Cancun, and the hottest year ever come and gone, you would think that global climate disruption was spinning up cyclones with reckless abandon.  Remember, after Katrina in 2005,  scientists published alarming papers linking increases in hurricane activity worldwide to global warming.  Fast forward 5-years: the inconvenient truth is that aside from the Atlantic basin, global tropical cyclone or hurricane activity during 2010 has tanked to the lowest levels in decades.

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So with all that under your belt, now read what Dr. Roger Pielke Jr. has to say:

At ClimateWire, Evan Lehmann has a lengthy overview (also here at the NYT) of a new paper by Ryan Crompton, John McAneney (both of Macquarie University) and me on detecting signals of human-caused climate change in disaster losses. Ryan, who is wicked smart, did the heavy lifting and heavy thinking on it and deserves credit for what should be a widely influential article.

Lehmann writes in the article:

Economic losses are seen as a potent storyteller about climate change. If greenhouse gases could be shown to increase financial damages, that might accelerate efforts to develop stronger buildings codes, influence insurance prices for coastal homes, and discourage development in risk-prone areas.

But the research tells a different story, at least for hurricanes. As a backdrop, it uses a landmark study published in Science last January finding that the number of strongest hurricanes, categories 4 and 5, could double in 100 years because of climate change.

The researchers begin by assuming that’s true. Then they apply hurricane damage data from the past century to those future hazards, adjusting for growth in population, inflation and wealth.

The results indicate that future hurricane damages won’t produce a tangible “climate signal” for at least 120 years, and perhaps not for 550 years. The average time before a signal might be seen is 260 years, according to the combined findings of an 18-model ensemble used by the researchers. In that year, 2271, climate change is expected to increase damage by 106 percent, more than double.

The researchers know this is a touchy topic. It could be perceived as an effort to downplay the impacts of climate change, or be seen with alarm by environmentalists advocating for action now to cut carbon pollution.

“It’s not to dispute that [global warming] is happening or what influence it will have on hurricanes,” said Ryan Crompton, a co-author and a catastrophe risk expert with Risk Frontiers, a research organization at Macquarie University near Sydney, Australia, that is funded in part by the insurance industry.

The study that we build off of is Bender et al. 2010 which argues that under their projected changes in the behavior of hurricanes a signal will not be detectable in the geophysical data until later this century.  If it takes that long to detect a signal in the geophysical data, it is just common sense that it will take longer to see that signal emerge in loss data.

…

The paper is forthcoming in Environmental Research Letters — here is the citation, abstract and concluding section:

Crompton, R. P.,  R. A. Pielke Jr. and K. J. McAneney, 2011 (forthcoming). Emergence time scales for detection of anthropogenic climate change in US tropical cyclone loss data, Environmental Research Letters V. 6, No. 1.

Abstract

Recent reviews have concluded that efforts to date have yet to detect or attribute an anthropogenic climate change influence on Atlantic tropical cyclone (of at least tropical storm strength) behaviour and concomitant damage. However, identification of such influence cannot be ruled out in the future. Using projections of future tropical cyclone activity from a recent prominent study we estimate the time it would take for anthropogenic signals to emerge in a time series of normalized US tropical cyclone losses. Depending on the global climate model(s) underpinning the projection, emergence time scales range between 120 and 550 years, reflecting a large uncertainty. It takes 260 years for an 18-model ensemble-based signal to emerge. Consequently, under the projections examined here, the detection or attribution of an anthropogenic signal in tropical cyclone loss data is extremely unlikely to occur over periods of several decades (and even longer). This caution extends more generally to global weather-related natural disaster losses.

Conclusions

This study has investigated the impact of the Bender et al [11] Atlantic storm projections on US tropical cyclone economic losses. The emergence time scale of these anthropogenic climate change signals in normalized losses was found to be between 120 and 550 years. The 18-model ensemble-based signal emerges in 260 years.

This result confirms the general agreement that it is far more efficient to seek to detect anthropogenic signals in geophysical data directly rather than in loss data [14]. It also has implications for the emergence time scale of anthropogenic signals in global weather-related natural disaster losses given these losses are highly correlated with US tropical cyclone losses (supplementary discussion and supplementary table 1). Our results suggest that the emergence time scales are likely to be even longer than those determined for US tropical cyclone losses given that different perils will have different sensitivities to future anthropogenic climate change and may even change in different directions. We note that US tropical cyclone losses may become increasingly less correlated with global weather-related records as the loss potentials of developing countries in particular continue to rise rapidly, irrespective of future changes in climate [15]. This means that the relationship between the signal emergence time in US tropical cyclone losses and global losses may weaken over time.

Based on the results from our emergence time scale analysis we urge extreme caution in attributing short term trends (i.e., over many decades and longer) in normalized US tropical cyclone losses to anthropogenic climate change. The same conclusion applies to global weather-related natural disaster losses at least in the near future. Not only is short term variability not ‘climate change’ (which the IPCC defines on time scales of 30 to 50 years or longer), but anthropogenic climate change signals are very unlikely to emerge in US tropical cyclone losses at time scales of less than a century under the projections examined here.

Our results argue very strongly against using abnormally large losses from individual Atlantic hurricanes or seasons as either evidence of anthropogenic climate change or to justify actions on greenhouse gas emissions. There are far better justifications for action on greenhouse gases. Policy making related to climate necessarily must occur under uncertainty and ignorance. Our analysis indicates that such conditions will persist on timescales longer than those of decision making, strengthening the case for expanding disaster risk reduction in climate adaptation policy [15].

But, people like Al and Joe will continue to push the idea that there is a short term linkage, because to do otherwise is counterproductive to their goal of trying to scare the hell out of people. And, of course, the statistical sophistry of Michael Mann supports the meme:

Mann hockey-sticks hurricanes: Hurricanes in the Atlantic are more frequent than at any time in the last 1,000 years

Yeah, right.