Courtesy Meredith P.
We've all heard about global warming, the undeniable fact that the Earth's temperatures rose (dramatically / sharply / noticeably – take your pick) from 1980 to 1998. (We've heard considerably less about the equally undeniable fact that from 1999 to present temperatures have held steady or even dropped, but never mind.)
We've all heard that carbon dioxide, released into the atmosphere when we burn coal, gas or other fossil fuels, is the (only / primary / most important) source of the warming. (The Earth also warmed during Roman and Medieval times, when fossil fuel consumption was vanishingly small. But never mind.)
And we've all heard how this warming is going to bring about floods, drought, storms, extinctions and other ecological disasters if we don't reduce out carbon output by (the end of the century / 2020 / tomorrow afternoon).
Those first two points can be tested through observation and experiment. The last one cannot. It's a prediction about the future, and you cannot observe something that hasn't happened yet. But you can always bolster your position by accurately predicting the past.
Now, that may seem like a waste of time – I mean, it's the past. We know what happened. But that's what makes it such a great laboratory. Y'see, scientific predictions are based on models. Scientists take all those observations and experiments, put them in a computer, and see where the trends lead. You can test the model by taking observations from some point in the past, crunching the numbers, and seeing if the results match what we know happened next.
And that's exactly what Richard Zeebe, James Zachos and Gerald Dickens did. In an online article published by the journal Nature Geoscience, these three scientists took the model used by climate researchers to predict future global warming and applied it to an episode of past global warming. Specifically, they looked at a well-studied period 55 million years ago when the Earth's temperature rose dramatically. They plugged the data from that warming into the model used to predict current warming, and they found....
It didn't work. The climate models being used today were unable to duplicate known conditions from the past. They weren't even close – the results were off by about 50%.
Emily Latella, call your office.
Courtesy Apollo13Ma (background photo), public domain and Mark RyanA study out of New Zealand says a warmer climate speeds up molecular evolution in mammals. The concept isn’t exactly a new one. Scientists have known that a warmer environment increases the pace of microevolution for other types of life, such as some plants and marine animals, but evidence that it affects mammals – which are warm-blooded (meaning their temperature is regulated internally) – has not been observed before.
Lead researcher, Len Gillman from Auckland University of Technology, said the result of the study was “unexpected”.
""We have previously found a similar result for plant species and other groups have seen it in marine animals. But since these are 'ectotherms' - their body temperature is controlled directly by the environment - everyone assumed that the effect was caused by climate altering their metabolic rate.""
Since DNA can potentially mutate each time a cell divides into two copies of itself, the faster (and more often) these divisions take place, the more chances advantageous mutations will be passed onto subsequent generations, and the faster microevolution takes place.
Gillman and his crew traced and compared small genetic changes in 130 pairs of related species that lived in different latitudes, focusing on a single gene in each pair. They then compared the gene against that of a common ancestor, and were able to determine which of the two mammals’ DNA had mutated (microevolved) more rapidly. The changes were small-scale, but the species living in the more tropical environment showed a faster pace in its level of molecular evolution.
The results of the study appear in Proceedings of the Royal Society B.
Last January, Bryan praised Barack Obama’s inaugural address for promising to make decisions based on observation, data and statistics. Bryan also said,
We will keep a watchful eye over the next four years to make sure that science policy adheres to the agenda and principles that our new president has set out.
So, how are things going so far?
Last week, the White House released a new report on climate change. Roger Pielke Jr., professor of environmental studies at the University of Colorado, says the study is seriously flawed. He finds the report relies on data that is old, narrow, non-peer reviewed, second- and third-hand, and contradicted by more recent, peer-reviewed studies. He specifically objects to claims that global warming is leading to more natural disasters. Such disasters are Dr. Pielke’s specialty, and he argues there is no such trend.
Back in February, Secretary of Energy Steven Chu said that global warming was going to destroy agriculture in California. Dr. Pielke (who is becoming something of a one-man band in reigning in the more outrageous claims of global warming) picked apart that one as well.
In March, Interior Secretary Ken Salazar removed gray wolves in the northern Rockies from the Endangered Species list. This action was first proposed by President George W. Bush just before he left office, but suspended by the incoming administration. Two months later, they decided that Bush was right to accept the unanimous recommendation of Fish and Wildlife scientists.
Mark hates it when I point out stuff like that…
Courtesy Mark RyanIs the wind being knocked out of the sails of the wind energy industry? A study to be published this summer in Journal of Geophysical Research seems to be pointing that way. Wind measurements in the Midwest and eastern parts of the United States in particular have shown a decline in the energy source.
Two atmospheric researchers, Sara Pryor (no relation to Science Buzz’s own Liza Pryor – or is she?) of Indiana University, and her co-author Eugene Takle, a professor at Iowa State University say their research shows a distinct drop in wind speed in areas east of the Mississippi River, especially around the Great Lakes. Wind speeds there have diminished 10 percent or more in the past decade, and an overall decline in wind has been taking place since 1973.
Global warming may be the cause. Differences in barometric pressure drive wind production. In a global-warming environment, the Earth’s polar regions warm more quickly than the rest of the globe, and narrow the temperature difference between the poles and equatorial regions. That reduced difference in temperature also means a reduced difference in barometric pressure, which results in less air movement (wind).
Peak wind speeds in western regions of the US such as Texas and portions of the Northern Plains haven’t changed nearly as much. Pryor speculates the reason the Great Lakes area shows the greatest decrease may be because wind travels more slowly across water than ice, and in recent years there’s been less ice formation on the Great Lakes. Changes in the landscape such as trees and new construction near instrument stations may have also skewed the research. Still, wind speed studies done in Europe and Australia showed similar declines there, adding credence to the Pryor and Takle findings.
There are detractors to the study. Jeff Freedman, an atmospheric scientist with a renewable energy-consulting firm in Albany, N.Y., says his research has revealed no definite trend of reduced wind speed. And even though research hasn’t been published yet, some climate models studying the effects of global warming seem to agree with Freeman’s findings.
But if Pryor’s and Takle’s study proves to be true, it could mean big losses to the wind energy industry, since a 10 percent drop in peak winds would mean a 30 percent change in how wind energy is gathered.
According to the Global Humanitarian Forum, the number of deaths “that result from the spread of disease, malnutrition and natural disaster caused by climate change” is roughly 300,000 people per year.
Read more about it here.
Courtesy steven.bussHere at Science Buzz, we sometimes have what might seem like a Through the Looking Glass attitude towards Earth Day and environmentalism. I, for one, litter filthy old cans all over my yard, comfortable in the knowledge that these cans will provide wonderful little shelters for the population of rats in my neighborhood. Sort of counter-intuitive, huh? Well check this out: after I get rats living in those cans, I’m going to use highly toxic chemicals to poison the little suckers in their homes. I will then plant sunflower seeds in my dead rat filled cans. So litter + poison + patience = a beautiful garden + delicious sunflower seeds.
Sophisticated environmentalism can be complicated like that.
It feels good though, doesn’t it? A little weird, but good.
Here’s another one (and this one comes from scientists who published in the journal Nature, not just from, you know, me):
Air pollution is fighting global warming!
Say what? We thought global warming was caused by air pollution.
Yes, but… think back to flowers growing from cans of dead rats. It’s like that, kind of.
See, yes, air pollution in the form of carbon dioxide (and other gases, but we’re dealing with CO2 here) is warming the planet. But CO2 isn’t the only junk we’re burping up into the atmosphere. Think about the grey brown haze you see over some big cities. Co2 is invisible, so what’s that stuff? Some of the chemicals we put into the atmosphere have the effect of absorbing sunlight, or reflecting it back into space. Some particles form the nucleus of water droplets in clouds, and cause the same amount of water in a cloud to be spread out among a much larger number of droplets, and more droplets cause light to be reflected and scattered more. It’s all part a phenomenon sometimes referred to as “global dimming”.
Some scientists believe that “global dimming” has had the effect of partially masking global warming; we aren’t as warm as we might otherwise be for the amount of greenhouse gasses in the atmosphere because a significant amount of solar energy has been prevented from reaching the Earth by other pollutants. So there’s that.
The Nature article, however, focuses on something else entirely. While many people might assume that plants have a harder time growing in our pollution-dimmed world, it turns out that they actually seem to grow better under a hazy blanket of pollution. The light-scattering effect of many air pollutants actually causes light to reach more plant leaves. So more photosynthesis is taking place under this diffused light than under direct sunlight. That means that plants are growing more, and growing plants suck up more carbon dioxide.
The scientists behind the study estimate that global dimming could be responsible for as much as a one quarter increase in plant productivity from 1960 to 1999, causing a 10% increase in the amount of carbon stored by the land.
This also means that as we have stricter air pollution controls, the rate of global warming probably won’t decrease as much as we’d have thought—there’d be less CO2 in the air, but because other pollutants would be reduced as well plants would be less productive, and suck up less of the CO2 that is released.
If your answer is "Nothing, yet," then you might consider stopping by the museum.
Minnesota's Water Resources: Impacts of Climate Change
Dr. Lucinda Johnson, National Resources Research Institute, University of Minnesota-Duluth
Thursday, April 9, 2009
7 - 8:30 pm in the Auditorium
Over the past 150 years, Minnesota's climate has become increasingly warmer, wetter, and variable, resulting in undeniable ecological impacts. For example, more recent changes in precipitation patterns combined with urban expansion and wetland losses have resulted in an increase in the frequency and intensity of flooding in parts of Minnesota. Learn about exciting new research which will develop a prediction model for future climate changes specific to Minnesota, and discover its potential economic and civic impact.
Check it out.
Want to do your little part to raise awareness of Earth's energy crisis? Turn out all your lights Saturday from 8:30 to 9:30 p.m. A rolling global blackout will be taking place to mark Earth Hour 2009, the third year such an observance is being made. Among the celebrity endorses of the power-free hour is the band Coldplay, which I assume will be playing an acoustic set if it's on stage during those hours. More than one billion people are expected to cut their lights for an hour around the world Saturday.
Two recent headlines:
Because, y’know, if you can’t win an argument through reason, and you can’t win it through fear, you can always fall back on that old standby, force.