The UN's pointman on desertification called Wednesday on participants at the next climate summit in Cancun to take urgent measures to prevent future disasters by staving off land degradation.

"Those most vulnerable to climate change live in the driest parts of the globe: look at what is happening in Pakistan where the rain should come as a blessing and ends up being a curse," Luc Gnacadja told AFP.

"We ask ourselves why efforts are concentrated on protecting the forests, while we know that what drives deforestation is land degradation. If we do not find a response to land degradation, which gets worse with desertification, people will continue to cut down trees."

Gnacadja, the executive secretary of UN Convention to Combat Desertification (UNCCD), called for a "serious accord" by the end of the year.

A new UN conference is due to be held in the Mexican resort of Cancun to try to build on a loose accord hammered out at marathon talks in Copenhagen in December last year that were widely regarded as a failure.

Cancun will host negotiators from November 29 to December 10 who are set to discuss a binding agreement on reducing carbon dioxide emissions that will replace the Kyoto Protocol, which expires in December 2012.

Drought currently affects at least 41 percent of the planet and environmental degradation has caused it to spike by 15 to 25 percent since 1990, according to experts.

Gnacadja has warned that drought could parch close to 70 percent of the planet's soil by 2025 unless countries implement policies to slow desertification.