US expert finds hurricane intensity under-reported in early years

This article from news.com.au is timely just after my post re a drop off in Australian deaths from climate disasters.
This is the Dr Chris Landsea who resigned from the IPCC some time ago because he was not being listened to. Heavens above, why would anyone expect the IPCC to listen to an expert.

www.news.com.au/story/0,10117,19949597-23109,00.html

Hurricane expert queries global warming
From: Reuters
By Jim Loney in Miami, Florida

July 29, 2006

HISTORICAL data on hurricanes is not accurate enough to conclude that they are becoming more ferocious or that global warming is to blame, as some studies have suggested, a noted storm researcher says.
In an article published in the journal Science, Chris Landsea, a leading researcher at the US National Hurricane Centre, challenged studies that found a dramatic jump in hurricane intensity in recent years.

The paper is the latest salvo in the debate among climate scientists on whether human-induced global warming is producing stronger hurricanes.

The argument reached boiling point during last year’s record-shattering Atlantic hurricane season, which produced 28 tropical storms and hurricanes including, for the first time in a single season, four of the most destructive Category 5s.

Because of improvements in technology, including more and better satellites, forecasters now produce more accurate estimates of a storm’s power, which could mean more hurricanes are now recognised as powerful Category 4 and 5 storms, Mr Landsea said.

“It’s a consequence of us better monitoring things the last 15 years than we did back in the ’70s and ’80s,” he said.

Some climate scientists argue that global warming is causing more intense hurricanes, which draw their energy from warm sea water. Sea surface temperatures have increased about 0.55C in the past three decades, they say.

Last year, respected researcher Kerry Emanuel of the Massachusetts Institute of Technology wrote in Nature magazine that the energy dissipated by hurricanes in the North Atlantic had doubled in the past 30 years.

Another study, by Georgia Institute of Technology researchers and published in Science, found the proportion of hurricanes reaching Category 4 and 5 had nearly doubled in the past 35 years.

Mr Landsea is among a group of scientists who say the impact of global warming on hurricanes is not clear, and the studies do not account for inaccurate information in storm databases.

“It’s not to say that global warming isn’t causing changes. I don’t dispute the fact that global warming is going on or that it can have an impact on hurricanes,” Mr Landsea said.

He said researchers had data from only two geostationary satellites to monitor storms in 1975. Now, much better pictures were available from eight satellites.

Today’s scientists could get readings on hurricanes around the clock, where only daylight images were available decades ago.

Together, the technology changes meant forecasters were more likely than in the past to determine that a hurricane had higher winds.

“The hurricane doesn’t change. But you’re getting a better analysis of how strong that hurricane is,” Mr Landsea said.

The Science article said reanalysis of historic data had found about 70 previously unrecognised Category 4 and 5 hurricanes in the eastern hemisphere from 1978 to 1990. Such a finding would weaken the argument that the number of intense hurricanes is rising.

“For some of the storms in the north Indian Ocean, if they were to occur today, we would say they are Category 4 or 5 and yet they are listed in the data as Category 3 or weaker,” Mr Landsea said.

A cyclone that hit Bangladesh in 1970 and killed up to 500,000 people was not even listed as a hurricane, he said.

2 thoughts on “US expert finds hurricane intensity under-reported in early years”

  1. Between better instrumentation and post WW2 urbanisation in the world’s tropical cyclone affected areas, this makes lots of sense. We didn’t know what we didn’t know (and didn’t measure) and now we know a whole lot more.

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