It also suggests the amount of aerosols that humans emit into the atmosphere could impact tree growth, as high levels of aerosols cause "global dimming", an effect that occurs when the levels of light reaching the Earth's surface fall.

BBC: Earth News - Cosmic pattern to UK tree growth

However, to build the dams often cause irreversible environmental damage despite the fact that the mills do not emit harmful CO2 emissions into the atmosphere.

FORBES: In Brazil, Protesters Shut Down World's Largest Hydro Dam Project

Approximately 1, 100 such units at more than 450 existing power plants emit 48 tons of mercury into the air each year, with 11 tons of that deposited on to U.S. soil and waters, says EPA. Those plants also release arsenic, lead and other heavy metals, all of which are considered hazardous and are therefore subject to clean air laws that require those facilities to use modern pollution controls.

FORBES: Coal Plants Belching Out Less Mercury

Many fossil fuel stocks have been profitable in recent years, but because neither the producers nor consumers pay to emit climate-warming carbon pollution into the atmosphere, those profits are grossly distorted.

FORBES: Fossil Fuel Divestment Is A Timely Issue For Investors

Venezuela uses electronic voting machines which register an elector's decision and then emit a printed receipt for the voter to deposit into a sealed ballot box.

BBC: Venezuela election vote to be audited

But you know, they also emit a lot of mercury, which ends up getting into our water and then back into our food chain.

NPR: Environmentalists Point Beyond Global Warming

The other, which faces a specialised type of solar cell made of a material called indium gallium arsenide, is sculpted into a structure called a photonic crystal that causes it to emit infra-red radiation selectively at the frequency best absorbed by the cell.

ECONOMIST: Solar power