Could Cosmic Ray Influence Climate By Charging Up More Frequent Lightning Storms?: ScienceDaily

Could cosmic rays be influencing climate by charging up more frequent lightning storms? European researchers hope to answer that question in the inaugural issue of the International Journal of Global Warming.

Several factors influence global climate change. Long-term influences that work over hundreds of thousands of years have an astronomical origin, namely the eccentricity, axial tilt and precession of the Earth's orbit. Natural processes on earth, such as volcanic activity and lightning also affect the levels of particulates in the atmosphere and so affect climate. Higher levels of particulates in the atmosphere increase cloud cover, which reduces the amount of energy from sunlight absorbed by the earth's surface.
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Heitor Reis and Cláudia Serrano of the Geophysics Centre of Évora, Portugal, point out that another factor must be considered in detailed climate models. They explain that on a shorter timescale, solar activity, which follows an eleven-year cycle, may have a subtle effect not previously recognised.
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When solar activity is close to its minimum cosmic rays will increase cloud cover and lightning, which will almost completely cancel out the warming effect of added greenhouse gases at that point in time.