Global warming: nearing a tipping point

According to new research by an international group of 18 scientists, published in the peer-reviewed journal Nature, Earth is rapidly headed toward a catastrophic breakdown, a tipping point marked by extinctions and unpredictable changes on a scale not seen in 12,000 years.

A tipping point in when increasing pressure on a system produces sudden, dramatic changes whose form can’t be exactly predicted even as the type and direction of changes can be. Think of blowing up a balloon: It will expand and expand, but at some point it will burst. In the same way, constantly putting more pressure on the environment will lead to a point of no return, producing major changes occurring in unpredictable ways.

The most recent example of one of these transitions is the end of the last ice age, about 12,000 years ago. Within about 3,000 years, the Earth went from being 30 percent covered in ice to being nearly ice-free. This also involved a wave of extinctions and ecological changes that occurred in little more than 1500 years. That may sound like a long time, but that is little more than a snap of the fingers in terms of geological time. And the changes we are causing now - including temperature increases - are both bigger and occurring more rapidly than those that ended the ice age.

Again, the results are difficult to predict; tipping points, by definition, produce results that can’t be predicted exactly. But based on past transitions, these scientists predict a major loss of species as well as changes in the makeup of species on the local level. As one of the scientists said,

You can envision these state changes as a fast period of adjustment where we get pushed through the eye of the needle. As we're going through the eye of the needle, that's when we see political strife, economic strife, war and famine.

Reflecting that sort of prospect, concern about global warming is spreading beyond the realms of climatologists and environmentalists. Public health specialists are increasingly concerned about the potential impacts on patterns of physical activity, food availability, and distribution of disease, among others. A paper published a couple of weeks ago in the peer-reviewed journal PLoS Medicine raised those issues and forecast an increase in diseases particularly affecting the poor, such as malaria and dengue fever, as well as heat stroke in drought-afflicted areas.

This is not the first time health officials have considered the potential human toll of climate change. In March, a group of doctors suggested that the incidence of asthma and other lung respiratory illnesses could increase as a result of global warming because it could lead to longer pollen seasons and to increasing the ranges of disease-causing molds and disease-carrying mosquitoes.

Meanwhile, here at home, the heat is on. According to NOAA, the average temperature for the 48 contiguous US states during May made it the second warmest May on record. Record keeping began in 1895, so that makes it the second warmest May in at least 117 years. We also had the warmest spring on that record, that is, the warmest spring in at least 117 years, the warmest year-to-date on record, and the warmest 12-month period on record. Besides the warmest spring, that 12-month period also included the second warmest summer and the fourth warmest winter. Forty-seven of the 48 contiguous states had warmer than average temperatures for the period; the only exception was Washington, which was near normal.

Now, as I often note, one event, even one year, is not proof of human-driven climate change. One hot year no more proves global warming than one cool year disproves it. The issue is the trend over time. But this is one more data point in a mountain - a growing mountain - of data points which all say the same thing: Humanity is screwing with the climate in ways harmful to our own future.

In fact, here's another interesting data point: Last July, scientists happened upon a massive phytoplankton bloom in the Arctic, one like none seen before. It covered 62 miles (100 km) and was dense enough to make the water a murky green. One scientist said it was like “finding the Amazon rainforest in the middle of the Mojave Desert." In fact, it was so much that the researchers initially thought something was wrong with their instruments.

The real shocker, though, was that the bloom was growing under thick sea ice, where sunlight is limited. A massive bloom in the dark, under the ice, was described a being a lot like a polar bear cub getting fat on a diet of nothing.

Researchers realized the bloom happened because the sea ice, instead of blocking sunlight, is melting and getting thinner, and the melt pools on the surface actually magnify sunlight. This creates conditions more favorable for algae than areas that have no ice cover. In other words, this is a visible effect of global warming that could presage a change in the ecosystem of the Arctic.

Global warming is real, it is driven by human activity, and it is having visible, measurable effects today.

So what are we doing about it? Late last year, officials from around the world met in Durban, South Africa to discuss climate change. At that meeting, the world's three biggest producers of greenhouse gases - India, China, and the United States, agreed to continue talking about possibly maybe someday limiting their carbon emissions.

Sometimes I am glad to know that I will not live long enough to see the world I see coming.

Sources:
http://www.huffingtonpost.com/2012/06/07/earth-tipping-point-study_n_1577835.html
www.usnews.com/news/articles/2012/06/05/expert-climate-change-will-increasingly-become-global-health-issue
http://www.care2.com/causes/immense-algae-bloom-signals-major-change-in-arctic.html
http://www.care2.com/causes/spring-of-2012-warmest-on-record.html
http://www.sciencedaily.com/releases/2012/06/120607185751.htm
http://www.usnews.com/news/articles/2012/03/15/doctors-warn-climate-change-may-lead-to-spike-in-asthma-cases