请教白勇一道题P124-6题

Citing evidence that the carbon dioxide content of the atmosphere has increased more than seven percent in the last 30 years, many scientists have expressed a fear of destroying forests and continued use of fossil fuels will cause an irreversible shift in Earth's climatic pattern.

answer is : change destroying forests  to destruction of forests

我的问题是不理解句子结构, scientists have expressed a fear and 句子(contiuned use of fossil fuels will cause an ..........) ?

express后面两个宾语,一个短语 一个省略that的从句?