Category: Environment

Researchers are reporting that the frequency of Atlantic hurricanes has doubled over the last century. 100 years ago, the Atlantic saw 6 severe storms a year, and now it experiences 15. The study concludes that warmer sea surface temperatures are to blame; changing wind patterns from global warming are fueling the increase in hurricanes.

This news comes from the most recent issue of the journal Philosophical Transactions of the Royal Society of London. The study is written by Greg Holland of the National Center for Atmospheric Research (NCAR) in Boulder, Colo., and Peter Webster of Georgia Institute of Technology.

The researchers identified three periods since 1900, separated by sharp transitions, where the average number of hurricanes and tropical storms increased dramatically, and then remained at this new plateau. The first period was between 1900 and 1930, with 6 major storms a year. From 1930 to 1940, the number increased to 10. And then it increased again to an average of 15 from 1995 to 2005.

The increases in storm frequency and severity match the levels of warmer surface sea temperatures, which have risen over the last century. As temperatures rise, this has created warmer ocean temperatures, fueling the storms. The article authors note that the rise in Atlantic Ocean temperatures have been attributed to global warming in many other studies.

This study goes on to discuss what role natural storm cycles might have in the increase they measured. They found that natural cycles can’t be the entire cause because the increase has happened over the last century, and hasn’t been oscillating in tandem with a natural cycle.

2006 might have seemed like a slow year for storms. Maybe today. But 100 years ago, it would have seemed normal, or even above average compared to average storm frequency.

Original Source: NSF News Release

Over the coming decades, we’re going to learn what kind of impact global warming is going to have on planet Earth. If the impact is as severe as some scientists are predicting, countries might take drastic action to stabilize temperatures. But scientists from Concordia University and the Carnegie Institution think that tinkering with the Earth on a global scale – or geoengineering – is very bad idea, and could make the problem much worse.

In order to defend against global warming, some novel ideas have been proposed; here are a few: building a fleet of satellites to shade the planet, using mirrors to reflect light away, or releasing light-reflecting particles into the atmosphere to cool temperatures.

According to this new study, published in the June 4 Proceedings of the National Academy of Sciences, these projects could provide relief from rising temperatures, but they could worsen the situation if the projects fail or were suddenly halted. Even though temperatures would be cooled, greenhouse gas emissions would continue to rise. And if the projects failed, we could experience rates of warming 20 times what we are experiencing today.

For an analogy, let’s say you want to keep your car cool, and put shades over the windows. If you take the shades off in the heat of the day, the car will heat up much more quickly than if you let it warm up slowly in over the course of the morning. This kind of drastic temperature increase would put even more of a strain on resources, wildlife, and human populations.

Here’s what one of the researchers, Ken Caldeira, had to say:

“Many people argue that we need to prevent climate change. Others argue that we need to keep emitting greenhouse gases,” Caldeira said. “Geoengineering schemes have been proposed as a cheap fix that could let us have our cake and eat it, too. But geoengineering schemes are not well understood. Our study shows that planet-sized geoengineering means planet-sized risks.”

The researchers aren’t ruling out these kinds of megaprojects entirely, but they emphasize cutting down emissions as quickly as possible, not hoping to rely on a silver bullet.

Original Source: Carnegie Institution News Release

The effects of global warming are already being felt worldwide, but the Earth’s poles are suffering the worst of it. Climate researchers have built a series of models to predict what impact rising temperatures will have on the amount of sea ice in the Arctic Ocean, and it appears they didn’t make these models conservative enough. Sea ice is being depleted at triple the rate that was predicted.

The research was reported in a new study by the National Center for Atmospheric Research (NCAR) and the University of Colorado’s National Snow and Ice Data Center (NSIDC). The authors compared simulations of of past climate to current observations on land and from space. The models estimated that ice would decrease at a rate of 2.5% per decade from 1953 to 2006. But the latest observations show that ice declined at an average rate of 7.8%. In other words, the decline of sea ice is currently about 30 years ahead of schedule from what researchers were originally predicting.

Several factors could have gone into the incorrect models, such as overestimating the thickness of present-day sea ice, or misunderstanding the atmospheric and oceanic circulation that transports heat to the polar regions.

Original Source: UCAR News Release