Global warming, what should we expect?

Global warming, once regarded as a theory, now receives attention from governments and supranational institutions (European Union or United Nations). Still, there is no consensus on the long-term effects of global warming. The lack of a consensus leaves people wondering if there is actually anything wrong with global warming. What is wrong with a few extra weeks at the beach? In the movie The Day After Tomorrow, global warming sent the world into another ice age. The idea is somewhat farfetched. Let me get this straight, global warming will back the wooly mammoth and saber-toothed tiger? I’m not buying it. A more probable result of climate change can be seen in the southeastern Asian country of Indonesia.

Halfway across the globe, Indonesia is no stranger to severe weather, suffering from flooding, droughts, tsunamis, earthquakes, and the occasional volcano. The country depends heavily on the Asian monsoon (seasonal winds that bring distinct weather conditions) to drive its weather patterns. The monsoons blow in certain directions depending on the time of year, which creates intense wet and dry seasons. Unfortunately, monsoon patterns are expected to intensify with global warming. In the January 18, 2006 edition of Nature, Jonathan T. Overpeck and Julia E. Cole write about changes in monsoon patterns affecting Indonesia. The article, “Climate Change, Lessons from a distant monsoon,” reports the shifting of monsoons over the island nation.

Indonesia, a country of 245 million people, relies on rainfall brought by the monsoon to support its agricultural industry. Reliance on crops like rice, rubber, cocoa, and coffee (the three latter all come from rainforest trees) give rainfall an important role in sustaining the nation’s economy. Given the fact that 43.3% of its labor force is concentrated in agriculture, shifts in monsoon patterns could be devastating for the island nation. Overpeck and Cole report that Indonesian weather patterns (and most of South East Asia) are affected by the El Niño/ Southern Oscillation (ENSO) system. El Niño (a rise in ocean temperatures in the central Pacific Ocean, concentrated off the coast of Ecuador and Peru) moves rainfall east of the islands, leaving Indonesia in a drought. The Indian Ocean Dipole, slightly less famous than El Niño, creates drought on the western side of the nation. The Indian Ocean Dipole results in cooler sea temperatures off the coast of Sumatra (Indonesia’s most westerly island).

Overpeck and Cole mention Asian monsoons are expected to increase in intensity with global warming. They do not entertain how and why this will happen, but monsoon intensification will cause an increase in drought conditions. Scientists have studied historical evidence in coral reefs to predict future climate conditions. The chemical composition of coral reflects the climate at the time of its formation, therefore providing scientists with a natural climate record. The historical evidence shows that Indonesia had stronger monsoons and longer periods of drought 5,000 years ago. According to Overpeck and Cole, “a stronger Asian monsoon generates anomalies in the easterly winds that would cool the eastern Indian Ocean.” In short, the anomalies in the wind keep the ocean temperatures in the eastern Indian Ocean cooler, creating the aforementioned drought conditions on the islands. As mentioned before, nearly half of Indonesia’s labor force is involved in agriculture. Challenges to the agriculture industry could hurt the nation’s economy.

Historical evidence from coral reefs also shows that monsoon patterns have undergone rather abrupt changes in the past. It would be naïve to exclude this as a possibility for the future. The abrupt changes are difficult to predict, which adds an additional variable to the equation. An abrupt change could bring seasons of intense rain, causing flooding through out the nation, or extreme drought, harming the agriculture industry. Since this is unpredictable, the nation would have very little - if any – time to adapt.

Post-industrial nations in Europe and North America do not face the same threats that changing monsoons will bring to Indonesia. Our agriculture is much less susceptible to climate changes, thanks to technologically advanced equipment and crops that require less water. It is likely that less developed nations will suffer more from the effects of global warming than developed ones. While we will not wake up one day and find that we are in another ice age, average temperatures will change. Rainfall amounts will, too. The effects in developed nations could be rather small. Will we be able to swim in December? Will we need umbrellas every day?

Who knows?

For the original text of “Climate Change, Lessons From a Distant Monsoon”:
Overpeck, Jonathan T. and Julia E. Cole. “Climate Change, Lessons From a Distant Monsoon.” Nature 445 (2007): 270-271.