THERE are human fingerprints on the global thermostat, says Britain’s Meteorological Office. A model that considers natural as well as man-made effects confirms that over the past 50 years human activity caused the most warming.
Natural volcanic aerosols and changes in solar radiation can affect climate, but most earlier models ignored them. The new model shows that natural effects over the past 50 years were actually cooling, leading to a slight underestimate of human-induced warming.
Over that period, natural effects and man-made sulphate aerosols each caused cooling of about 0.3 °C per century, says the Met Office’s Gareth Jones. Taken…
