Saturday, May 10, 2008

The effects climate change has on water and living things

Argen Duncan El Defensor Chieftain Reporter

Climate change is affecting temperatures, water and living things around the globe, and threatens to make the Southwest hotter and drier, said New Mexcio Tech students.

As part of their environmental chemistry class, the students gave a public seminar on climate change April 30.

Evidence and Effects of Climate Change

In one presentation, biology master's student Adam Mott and sophomore majoring in chemical engineering Daniel Veghte presented evidence of climate change.

Temperature has increased 0.2 percent per decade and three Scandinavian cities have seen rising sea levels over the last 300 years, with an acceleration rate of 0.05 inches per century, Veghte said. However, the sea level rise hasn't been uniform, as the Western Pacific Ocean has increased a lot while the Eastern Pacific experienced a small drop.

Veghte said 27 percent of the change in sea levels comes directly from human actions and another 27 percent is due to thermal expansion of the oceans.

Also, Veghte said glaciers shrank 0.98 feet per year between 1980 and 1990, but 4.92 feet in 2006.

Artic ice is decreasing and may be gone during summers (but not winters) by 2070, Veghte said. Then a Northwest Passage north of Canada would become a viable shipping route and people might exploit large natural gas resources that could become available.

Those occurrences could increase greenhouse gas emissions.

As for climate change effects on human health, Mott said heat stress could especially hurt the very young and very old. Also, the climate change could favor the type of mosquito that carries malaria and the bubonic plague bacteria, increasing instances of the diseases.

Scientists are unsure of the effect on hantavirus.

"And right now studies are mixed," Mott said.

Global warming could also hurt polar bears and caribou, confuse the migratory timing of birds and destroy coral reefs.

Mott said natural selection probably wouldn't work fast enough to keep up with the environmental changes. Many species would die, but some would benefit, he said.

After the presentation, an audience member asked whose fault past climate change was. Pullin said the earth has experienced natural cycles but that doesn't mean humans are influencing the climate.

Effects of Global Warming

on the Southwest

In the following presentation, doctoral student majoring in geology Amy Luther said the Southwest has a unique climate with moisture patterns dictated by westerlies in the winter and ocean-controlled monsoons in the summer. The area experiences droughts with intermittent floods.

The periodic ocean-storm system El Niño brings more moisture to New Mexico, while the system La Niña means drier weather, Luther said. She said global warming heats ocean surface temperatures, which leads to predictions for drier weather in New Mexico.

Recently, New Mexico and Arizona have seen average temperature increases. Luther said all climate models predict drought, more heat and devastating floods for the Southwest.

Environmental science senior Whitney DeFoor said higher temperatures mean drought, less water due to less snow pack, warmer and shorter winters that allow less opportunity for the weather to kill pests, and less sap on trees to protect them from the bark beetle. She also said the increased warmth would allow plants that normally live at low elevations to move into higher elevations.

In addition, DeFoor said woody plants like trees benefit more directly from increased levels of carbon dioxide than do grasses. Trees could take over grasslands due to higher carbon dioxide levels.

"So as you can see, this isn't going to be good news for the ranchers, who are alreadcy having trouble with this now," DeFoor said.

As for water, geology master's student Josh Feldman said irrigation and public water uses such as sanitation could have less water available. Less water would mean less grass for ranches, he said.

Also, Feldman said public water policy would have to change because current New Mexico laws require that water rights owners use their water, however inefficiently, to keep the rights.

"This is one of the things that's going to have to change as water gets scarcer and scarcer," he said.

Feldman said Lake Mead, the snow-fed home of Hoover Dam, is at two-thirds of its capacity.

"It's happening all across the Southwest," he said.

With the Rio Grande fed from snow melt, Feldman predicted, less snow would affect everyone in New Mexico.

Also, since manufacturing uses a lot of water, Feldman said, if water prices rise with drought, consumers prices would increase and employment would be affected.

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