Volcanic potentialPosted: March 7, 2011
Active volcanoes are an X factor in climate change, says naturalist Michael Ricciardi.* Explosive eruptions eject ash and smoke into the upper atmosphere, forming a shield to deflect solar radiation from reaching the Earth.
Consider the Toba eruption. The Pleistocene, the seventh major Ice Age that geologists have recorded, started perhaps some 1.7 million years ago, although scientific opinions differ and the cooling may have begun much earlier. About 73,500 years ago, during the Pleistocene, a super-volcanic eruption in the Lake Toba region of the Indonesian island of Sumatra triggered severe further cooling.** The vast clouds of gases and ash emitted from the volcano included sulphur dioxide which was converted to sulphuric acid in the upper atmosphere. This formed a barrier between Earth and the sun’s energy, sending heat straight back. The eruption may have cooled the Earth by three to five degrees C, a cataclysmic event resulting in species extinctions and probably a drastic reduction in the numbers of humans. They died from suffocation by ash and gases, and from the long-lasting catastrophic impact on their food sources.
Toba may be an extreme case, but volcanoes are risky environments, and in poor countries already struggling to cope with climate change, an eruption can be tragic both immediately and far into the future.
A chain of volcanoes puncturing the skylines of Central America extends from Mexico to Panama through Guatemala, El Salvador, Nicaragua and Costa Rica. Pacaya in Guatemala — pictured above — is the second most active in Central America (after Santa Maria, also in Guatemala) and you can hike down into the crater, step across red-hot lava, and dry your wet clothes if you have had a drenching on the climb up. Volcanoes are big if unstable magnets for tourism: the village of San Francisco de Sales, on Pacaya’s slopes, caters for the daily influx with supplies of plastic macs, walking sticks and ponies for the less agile hikers.
El Rincon de la Vieja, an active volcano in Costa Rica’s northern Guanacaste province, is also a top draw for tourists. On our visit in February I saw, hiking the same trails, two groups who had been on the Saturday plane out from Madrid to San José. We had an expert guide, Javier, who answered every question fluently in English — Costa Rica’s education system is hot on languages — and showed us boiling water, bubbling mud and smoking fumaroles.
All this geothermal energy has the potential to replace much of the fossil fuel that Costa Rica imports to generate power. We passed a new geothermal energy plant as our bus bounced up towards the lower slopes of the volcano.
Over the border in Nicaragua, at the Telica volcano, the San Jacinto-Tizate geothermal project is scheduled to produce 82MW of electricity in 2012, and ultimately over 200MW. The Inter-American Development Bank has loaned $40 million of the $177 million cost of the second phase of the project, which is in the hands of Polaris Energy Nicaragua, a subsidiary of Ram Power Corp of Reno, Nevada in the USA.
Tapping geothermal energy from a volcano comes with the risk that a big eruption could destroy the power plant as well as people, homes and farmland, but increasingly the cost-benefit equation comes down in favour of the energy. Volcanoes are magical places for visitors, but volcano tourism is likely to suffer in coming years as long-haul travel costs escalate, while these same pressures, forcing fuel and power prices up, turn geothermal power into a vital resource. Nicaragua, with six active volcanoes, and Costa Rica with five, are set to become influential epicentres of geothermal energy, their people hoping that their volcanoes will smoulder and steam quietly for decades to come, and that they will be spared from any destructive explosions.
* ‘Volcanoes: the X Factor in Climate Change’, www.planetsave.com, April 19th 2010.