Global Warming Plays Favorites

Just as we thought the entire world was doomed, we learn that global warming chooses favorites, and one of them is in Australia.

Earlier this week, researchers at the University of Adelaide stumbled on a magical lake that at first blush looks too pretty to be real. The magic? The body of freshwater simply known as Blue Lake has been almost completely untouched by climate change for the last 7,000 years.

One of the largest lakes on North Stradbroke Island, Blue Lake runs deeper than ten meters, though the water’s clarity allows for a visible bottom. The lake’s pristine state is unheard of in today’s global-warming-destroys-everything scenario, which is why the media harped on initial news of discovery. Google ‘God’s bathtub’ and you’ll see what I mean.

The lowdown: Researcher Dr. Cameron Barr and his team were studying the effects of drought on freshwater when they came across the unique lake. The team looked at several measures of environmental change, including fossil pollen, fossil algae, and diatoms, Barr told Australian Broadcasting Corporation. Through the diatoms, they found nothing--as in no changes to the water’s chemistry. Barr said this represents the only lake in Australia to show this much stability.

"In that sense it's a refuge for freshwater biota away from those variable environments,” Barr told ABC. "And we would argue that it's likely to be a freshwater refuge for some time in the future if managed properly."

As the hype may suggest, it's an uncommon finding. In her book Impacts of Climate Change and Climate Variability on Hydrological Regimes, Jan van Dam shows that, although not entirely invincible to climate change, properly maintained freshwater won’t suffer as much devastation. “Climate change is more likely to affect polluted bodies of water more significantly than clean ones,” van Dam wrote.

According to Barr, Blue Lake stays clean because it drains into a swamp and is constantly refreshed by an aquifer. He said Blue Lake doesn’t become cleaner, but it remains constant.

Van Dam goes on to argue that the deterioration of water quality is more serious in developing countries than in industrialized ones due to more lenient pollution control regulations. Although Australia, a highly developed country, has strict pollution regulations, there are other factors at play that make the results surprising.

In her book, van Dam points out that elevated levels of CO2 within countries, and in turn their bodies of water, cause a reduction in pH and an increase in salinity, eventually leading to eutrophication. Australia’s level of carbon emissions per capita is among the highest in the world at 18.8 tons in 2007, according to the Australian Bureau of Statistics, but the lake still remains pure.

Drought also has devastating effects on water quality. Besides the obvious lack of rain, reduced water runoff means less dilution, which generally increases salinity and pollution in water. Drought is frequent in Australia, yet it’s accompanied by major flooding which could offset the potential damage to bodies of water.

Blue Lake will most likely prove to be the only one of its kind in Australia and the world. Dr. Tim Barnett, a research marine physicist at the Scripps Institution of Oceanography, hasn’t seen anything like it before, calling it a very “interesting” place that could still see changes in the future.

“As the atmosphere gets warmer, water will increasingly evaporate from the oceans and lakes and increase the moisture in the atmosphere," Barnett wrote in an email. "As the long wave pattern shifts, so will regions of enhanced and decreased precipitation associated with the increased evaporation. Some loser and some winners in this game.”

Dr. Steven Wilhelm, a professor of microbiology at the University of Tennessee, also predicts patterns in the future that could change Blue Lake’s purity.

“I think lakes tend to age and evolve, perhaps like cheese or wine. So they are meant to change, and the question is how much is natural and how much is due to global change or simply direct human impacts,” Wilhelm wrote in an email.

So I guess it’s true. Global warming does have favorites, if only for a little while.