evidence: This includes making corrections to the time series of temperature records to account for variations in the location or environment of an observation station, or changes in the measurement techniques of historic temperature records. This monitoring makes us certain that increasing global temperatures are due to human activities since the industrial revolution, when the burning of fossil fuels started injecting huge levels of greenhouses gases into the atmosphere. [...] The sun provides all the energy for the Earth’s climate. This means any changes in its radiative output also have a strong potential to influence global atmospheric and ocean temperatures. Scientists have measured solar radiation using satellites over the past forty years, and have looked at indicators of solar activity over much longer periods in geological data. This evidence shows us that, over the past 10,000 years at least, the sun’s energy has varied by less than one tenth of one percent. This is enough to have caused variations in global temperature of around 0.1°C, but cannot explain the global warming of around 1°C over the past century[2]. [...] These natural variations in solar radiation are subtle, and scientists know they are too weak to build an Ice Age by themselves. However, their effect is amplified by feedback loops that make them stronger. For example, when the Earth’s surface turns white due to increased snow and ice cover, it becomes more reflective and so cools the planet further. Variation in CO2 levels is also an important feedback loop in creating an Ice Age. Part of this feedback loop relates to changes in how much CO2 the ocean stores.