Whether the human population is intending to alter the climate or not, it definitely is. Recent environmental science budget cuts suggest that our carbon emissions are going to reach zero anytime in the recent future, so some scientists, including Harvard Physicist David Keith, plan to experiment with geoengineering to slow the overall heating of the earth.
The global heating of the earth is caused by greenhouse gasses due to the fact that heat from the sun can enter the earth in the form of radiation but the resultant heat from the radiation hitting the earth's surface has trouble escaping through the gasses, especially as they build up. Keith plans to experiment with a strategy in which he and his team are going to experiment with an artificial cloud to see how well it reflects the sun's radiation. One case in which this strategy has been the eruption of Mount Pinatubo in the Philippines in which the volcano shot 14 megatons of sulfur dioxide into the atmosphere blocking some of the sun's radiation resulting in about a 1 degree fahrenheit lowering of the earth's surface. Although this strategy appears to probably work, the 1992 Mount Pinatubo eruption may have been the direct cause of precipitation pattern shifting, which the Mississippi river flooding and African Sahel drought could have been results of.
Although this could lower the temperatures of the planet, it would have no effect on the amount of carbon in the air, and for that, scientists would need another plan.
For now, the whole idea of geoengineering the earth is in a testing stage including Keith's test which would deploy an artificial cloud at 12 miles and collect data to see if the whole idea would be able to fulfill its purpose of reflecting and some of the sun's radiation and scattering the light. This test is scheduled to occur in 2018 to add data to the collection to better inform the future of possible decisions on the problem of global warming.
As Keith said, "The next generation will make decisions about this, say in the 2040s or 50s. A question is, do we have a research program that tells people more about how well it works or doesn't work, how big the risks are, and how you might manage those risks? If we have a coherent research program like that, I think we give the next generation more information to make a better decision. I'm not promoting some master plan. My intention is to push for a larger international open research program, mostly owned by the environmental community. It's not my decision to make."