A reanalysis of the effect of black carbon emissions has found that it is second only to carbon dioxide emissions in its warming impact on the climate. Together carbon dioxide, black carbon, and methane emissions represent the anthropogenic sources with the largest impact on Earth’s climate.
Oxygen is fundamental to oceanic biological processes and its decline can cause major changes in ocean productivity and biodiversity. Over the past 50 years low oxygen zones in the open oceans have expanded by an area equivalent to half the size of Canada and hundreds of coastal sites now have low oxygen concentrations that limit the distribution and abundance of animal populations.
Evidence that methane emissions from natural gas production have been considerably underestimated by the EPA was recently reinforced by the initiation of an investigation into how the EPA estimates methane emissions by the EPA’s Inspector General. If it is found that emissions of methane from natural gas production are considerably greater than current estimates, the advantage that natural gas has over coal will be eroded and the advantage of switching to natural gas as a cleaner form of energy diminished.
Based on the trend that greenhouse gases are increasing rapidly whereas solar irradiance is changing much more slowly, the evidence reveals that the climate impact of changes in solar irradiance are much smaller in magnitude than the increase in warming due to greenhouse gases.