One of the most difficult things to model with respect to climate change is the effect of aerosols, some of which reflect sunlight back up into space, thereby cooling the globe. Both human and natural activity create them. One piece of the puzzle is how to model the effect of the aerosols created by pine forests — but as the BBC reports, there has been a breakthrough:
One of the most significant but least understood sources of aerosols are the sweet-smelling vapors found in pine forests in North America, northern Europe and Russia. These aerosols have confounded climate models as scientists haven't been able to accurately predict how many of the particles form. Now an international team of researchers say they have solved the chemical mystery by which the rich odors become reflective, cooling particles.
Should world society fail to control carbon emissions, this could potentially be very helpful for future emergency geoengineering efforts, the most feasible of which involve dumping tons of aerosols into the atmosphere. Those aerosols probably wouldn't be pine vapors, though: in such a situation it will be important to understand the effects of that class of chemicals as thoroughly as possible.