One of the 70 authors of a draft United Nations report on climate change is assailing the report as highly "alarmist" with very few offered solutions.

That's why Richard Tol, an economics professor at the University of Sussex and also professor of the economics of climate change at the Vrije Universiteit Amsterdam, announced he was pulling out of the development process for the document, expected to be introduced in Japan March 31.

"The drafts became too alarmist," Tol told Reuters in a telephone interview from Yokohama, Japan, where government representatives and scientists are meeting to edit and finalize the report. On the other hand, he acknowledged at least some of his fellow editors "strongly disagree with me."

The climate change assessment says global warming will disrupt food supplies, slow economic growth and is likely already causing irreversible harm to undersea environments and, specifically, the Arctic.

Tol told Reuters the Intergovernmental Panel on Climate Change is much more focused on perceived risks of climate change than on opportunities the world's populations might find to adapt to the impending shifts. A Reuters survey of the final draft found the term "risk" mentioned 139 times, while the term "opportunity" was used a total eight times.

The IPCC summary, according to materials posted at the group's website, indicates a warming trend of 2.5 degrees Celsius (4.5 Fahrenheit) above pre-industrial periods will cause a reduction of global economic income by between 0.2 and 2.0 percent annually.

Tol countered that farmers, for example, could learn how to grow new, different crops, should their respective climates grow hotter, wetter or drier.

"Farmers are not stupid," he said. "They will adapt."

Likewise, the report seemed to de-emphasize any potential economic benefits resulting from climate changes, such as warmer farming regions where certain crops may have an easier time growing. Then, as well, warmer environs could lead to fewer cold-related deaths among the sick or elderly.

"It is pretty damn obvious that there are positive impacts of climate change, even though we are not always allowed to talk about them," Tol said.

In statement, the IPCC noted Tol -- who serves as coordinating lead author of a sub-chapter about economics and had been invited to Japan to help the drafting -- quietly announced in September that he was withdrawing from the team writing the summary.

The report is intended to assist governments in their efforts to cut rising greenhouse gas emissions, mainly by shifting from fossil fuels to renewable energies.