The IPCC refutes any scientific findings that suggest that global warming is not exclusively due to increased CO2 production from the burning of fossil fuels. In reality, 99.98 percent of the total energy contribution to the earth's climate originates from the sun. Solar irradiation is not constant but varies slightly in repeating cycles, which bring about significant climate change. Sunspots are an indication of solar activity and the strength of the sun's magnetic field, which forms a protective shield against the bombardment of cosmic rays streaming in from space. The weaker the field, the more cosmic rays that can reach earth. Cosmic rays influence cloud formation and are the most consistent factor in identifying the sun's current effect on climate. During the last two decades, sunspot activity has drastically diminished, and the earth may now be at the beginning of the next solar hibernation cycle — i.e. less energy from the sun, more cosmic rays and global cooling.