Last weekend I saw the documentary Six degrees that could change the world, by the National Geographic Channel. In short, it shows in good detail what would be the effects of global warming, for each degree of temperature increase in our planet:

• One degree: Where we are now [See here]

• Two degrees: Marine life in danger [See here]

• Three degrees: Victims of the heat wave [See here]

• Four degrees: The great cities are submerged [See here]

• Five degrees: The collapse of civilization [See here]

• Six degrees: Mass extinction? [See here]

Although most of the effects are known by everybody, it is shocking the explicit way it is shown. It is scary, because almost everyone thinks that global warming just means wearing T-shirts in summer, but the reality is more like a mixture of Soylent Green, the Katrina Effect and Children of Men in a dystopian future right out of our worst nightmares.

Speaking in concrete numbers

Writing down the figures shown in the documentary, the Climate Change 2007 report prepared by the IPCC (Intergovernmental Panel on Climate Change), conservatively describes what the effects of climate change would be:

• According to the agency estimates, the average global temperatures will increase by 1.4 °C and 5.8 °C by 2100. However, this is just an average: there will be regions and continents where these ranges can be much higher.

• We must think of this problem on a very long term, due to what we do today, will not have a direct effect until decades or centuries later: global warming that we suffer today is caused by gases that were released decades ago. For example, CO2 can persist in the atmosphere up to 200 years, and gases like Perfluoromethane (CF4) can stay up to 50,000 years in the atmosphere.

• According to the same report, the sea level will rise from 20 to 88 centimeters (7.88 to 34.65 inches) by 2100. This already represents a threat to islands such as Kiribati or countries with deltas that flow into the sea such as Egypt and Bangladesh; however there is new evidence that suggests that this is too optimistic: according to James Hansen’s study, titled Climate change and trace gases, “… the geological record suggests that ice at the poles does not melt in a gradual and linear fashion, but it suddenly changes from one state to another. When temperatures increased between 2 and 3 degrees above the current average 3.5 million years ago, the seas did not increased their level by 59 centimeters (23 inches) but by 25 meters (82 feet). Ice responded immediately to changes in temperature…”

Pic: Mexico 2100

Pic: South America 2100

Pic: Europe 2100

If predictions are correct and sea level rises 20 meters, many of the regions we know or inhabit today will cease to exist. In the case of Mexico, cities like Veracruz, Coatzacoalcos and Merida will be a fading memory. In South America, cities such as Rio de Janeiro and Montevideo will have its own Katrina effect, while Buenos Aires will not longer exist. In Europe the situation is not much better: while London might be saved, the Netherlands and cities like Hamburg and Venice will be the subject of underwater archeology.

• The annual cost to mitigate global warming’s effects can vary between $78 and $1,141 billion dollars, representing 0.2 to 3.5% of global gross domestic product. That is severe: to get an idea of how much it is, if each country pays for its share of a “global disaster relief fund,” Mexico would have to pay some $ 29.4 billion, in the worst case. Considering that Mexico’s federal budget is of about $ 209 billion, we would need to incur on extra expenditures of 15%, which obviously we don’t have.

• There is a chance that 20 to 30% of animal and plant species around the world will become extinct, according to current trends. If the average temperature exceeds 3.5 ° C, the extinction rate may rise to 40 – 70% world-wide. For reference, the K/T Event, which resulted in the extinction of dinosaurs, meant the loss of “only” 50% of species on the planet.

• The continued melting of glaciers and little or no replenishment of water sources due to increased temperatures would create a water crisis that can lead to wars over the valuable resource. For the particular case of Mexico, considering the already complicated relations with our northern neighbors (United States), adding water disputes can lead to conflicts such as those between Israel and Lebanon of recent years.

Nota final

Due to scandals involving errors and omissions in the report presented by the IPCC, at the moment there is a sizeable amount of people (especially blogs) assuming that the whole concept of global warming is just a farce. Well, as high-school Professor Greg Craven conveniently explains in this YouTube video, if we perform a small risk analysis where we have the following decision matrix:

Does Climate Change Exist? / What action do we take? Mitigate Climate Change Do Nothing
False (there is no climate change/ it has a natural origin) Costs associated with Green Economy = World Depression. Nothing happened here.
True (our greenhouse gas emissions are the cause) We managed to mitigate global warming Judgment Day

• If climate change is false, and we do nothing… then nothing happens, but the climate is increasingly unpredictable, warmer summers and honestly… Has no one noticed that not everything is as it should?

• If climate change is real and we do nothing… the world ends.

• If climate change is false and we make mitigation efforts… we are making an unnecessary expense, but in my personal opinion this mitigation may include incentives for cleaner industry, technology transfers as recommended by the Kyoto protocol, etc. that would result in a good choice.

• If climate change is real and we try to mitigate it… we are attacking the problem before it presents itself in full swing (remember: the wood that our grandfather burned decades ago continues to float over our atmosphere).

Therefore, on the meantime we better get accustomed to the idea of being greener, before it is too late and we realize that for saving a few cents now, tomorrow we have to pay thousands in repairs.

Update 09/06/2009

Climate change is in fact real, and we now have figures that support such claims: according to a report published by the Global Humanitarian Forum a few days ago:

… more than 300,000 people a year are dying from the effects of climate change. That figure is expected to rise to a half-million annually by 2030.

In addition, climate change is already having a serious impact on the lives of 325 million people, a number that will likely reach 660 million in 20 years. By affecting 10 per cent of the world’s population, that makes global warming the planet’s largest emerging humanitarian challenge.

[Finally] The economic costs of climate change are also steep, the report finds. Losses today total more than $125 billion a year – a figure that’s greater than the total amount of annual aid that currently flows from industrialized countries to developing nations. By 2030, the economic losses due to climate change will have almost trebled to $340 billion annually.

So, if anyone had any doubts about global warming and what 6 degrees of temperature imply, there you have it: the report gives specific numbers on lives and dollars lost already happening. So either we act now or we are screwed. From that same report:

If we don’t reverse the current trends by the end of 2020, we have failed. Global warming will have exceeded the known danger level of two degrees, since there is a delay of 20 years from the emission reduction and disruption of its warming effect. This report clearly shows that climate change is already dangerous below one level of warming. Two degrees would be catastrophic.