The effects of climate change cut across many sectors of the economy, the report says, pointing as an example to the conclusion of scientists and economists that warming-induced ocean acidification could cut the shellfish harvest in the Pacific Northwest by as much as half in the next 80 years. The annual burning of forestland in the Rocky Mountains could grow by 1.9 million acres over that same time period, according to an exhaustive national climate study conducted by the Rhodium Group, a multinational research firm, that is cited frequently in the congressional report.