Provide your best answer for the following question. Give ONLY the answer, no other words or explanation.
For example:

Answer: <most likely answer, as short as possible; not a complete sentence, just the answer!>.

The question is: After a period of steady increase, the rate of coal consumption was 50% higher during 2009 than it was during the year 2000. If this trend continues, which impact will coal consumption most likely have on the environment after the year 2010?
Increased pollution.