The evidence of climate change from observations of the atmosphere and surface has grown significantly in recent years. New methods for characterizing and quantifying uncertainty have highlighted the challenges in developing long-term global and regional climate data records. Observations of the atmosphere and surface indicate the following changes: Atmospheric Composition: Well-mixed greenhouse gases (GHGs) targeted by the Kyoto Protocol have increased in atmospheric burden from 2005 to 2011. Atmospheric CO₂ was 390.5 ppm in 2011, 40% higher than in 1750. Atmospheric N₂O was 324.2 ppb in 2011, having increased by 20% since 1750. Methane (CH₄) was 1803.2 ppb in 2011, 150% higher than before 1750. CH₄ began increasing in 2007 after remaining nearly constant from 1999 to 2006. Hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulphur hexafluoride (SF₆) continue to increase rapidly, but their contributions to radiative forcing are less than 1% of the total by well-mixed GHGs. Ozone-depleting substances (ODSs) show decreasing global mean abundances of major chlorofluorocarbons (CFCs) and some halons since 2005. HCFCs, which are transitional substitutes for CFCs, continue to increase, but their spatial distribution is changing. Radiation Budgets: Satellite records of top of the atmosphere radiation fluxes have been extended since AR4, and it is unlikely that significant trends exist in global and tropical radiation budgets since 2000. Interannual variability in Earth's energy imbalance related to El Niño-Southern Oscillation is consistent with ocean heat content records within observational uncertainty. Temperature: Global Mean Surface Temperature has increased since the late 19th century. Each of the past three decades has been successively warmer than all previous decades in the instrumental record, and the first decade of the 21st century has been the warmest. The globally averaged combined land and ocean surface temperature data show a warming of 0.85 [0.65 to 1.06] °C over 1880–2012, and about 0.72°C [0.49°C to 0.89°C] over 1951–2012. Hydrological Cycle: Confidence in precipitation change averaged over global land areas since 1901 is low for years prior to 1951 and medium afterwards. Averaged overThe evidence of climate change from observations of the atmosphere and surface has grown significantly in recent years. New methods for characterizing and quantifying uncertainty have highlighted the challenges in developing long-term global and regional climate data records. Observations of the atmosphere and surface indicate the following changes: Atmospheric Composition: Well-mixed greenhouse gases (GHGs) targeted by the Kyoto Protocol have increased in atmospheric burden from 2005 to 2011. Atmospheric CO₂ was 390.5 ppm in 2011, 40% higher than in 1750. Atmospheric N₂O was 324.2 ppb in 2011, having increased by 20% since 1750. Methane (CH₄) was 1803.2 ppb in 2011, 150% higher than before 1750. CH₄ began increasing in 2007 after remaining nearly constant from 1999 to 2006. Hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulphur hexafluoride (SF₆) continue to increase rapidly, but their contributions to radiative forcing are less than 1% of the total by well-mixed GHGs. Ozone-depleting substances (ODSs) show decreasing global mean abundances of major chlorofluorocarbons (CFCs) and some halons since 2005. HCFCs, which are transitional substitutes for CFCs, continue to increase, but their spatial distribution is changing. Radiation Budgets: Satellite records of top of the atmosphere radiation fluxes have been extended since AR4, and it is unlikely that significant trends exist in global and tropical radiation budgets since 2000. Interannual variability in Earth's energy imbalance related to El Niño-Southern Oscillation is consistent with ocean heat content records within observational uncertainty. Temperature: Global Mean Surface Temperature has increased since the late 19th century. Each of the past three decades has been successively warmer than all previous decades in the instrumental record, and the first decade of the 21st century has been the warmest. The globally averaged combined land and ocean surface temperature data show a warming of 0.85 [0.65 to 1.06] °C over 1880–2012, and about 0.72°C [0.49°C to 0.89°C] over 1951–2012. Hydrological Cycle: Confidence in precipitation change averaged over global land areas since 1901 is low for years prior to 1951 and medium afterwards. Averaged over