Wildfires spreading as temperatures rise

Janet Larsen of the Earth Policy Institute in IPS: Future firefighters have their work cut out for them. Perhaps nowhere does this hit home harder than in Australia, where in early 2009 a persistent drought, high winds, and record high temperatures set the stage for the worst wildfire in the country's history.

On Feb. 9, now known as "Black Saturday", the mercury in Melbourne topped 115 degrees Fahrenheit (46.4 degrees Celsius) as fires burned over one million acres in the state of Victoria - destroying more than 2,000 homes and killing more than 170 people, tens of thousands of cattle and sheep, and one million native animals.

Even as more people move into fire-prone wildlands around the world, the intense droughts and higher temperatures that come with global warming are likely to make fires more frequent and severe in many areas. For southeastern Australia, home to much of the country's population, climate change could triple the number of extreme fire risk days by 2050.

…Fire patterns have changed over time as human populations have grown and altered landscapes by clearing forests, allowing pasture animals to overgraze grasslands, and importing new plant species. Across parts of the western United States, for example, cheatgrass, an invasive annual adapted to frequent burns, has supplanted native brush, desert shrub, and perennial grasses that typically experience longer intervals between fires.

...Just as a weakened immune system leaves a person vulnerable to otherwise innocuous germs, the combination of logging, road construction, and intentional burning to clear forests for cattle ranches, farms, and plantations has fragmented the world's tropical forests, increasing their vulnerability to fire.

Piling higher temperatures on top of such stresses could completely undermine forests' resilience. For the massive Amazon rainforest, we risk reaching a tipping point where recurrent droughts dry out the landscape enough so that small fires can turn into devastating conflagrations….

Canberra bushfires in 2003, shot by Saperaud