The temperature increase on the Earth's surface has been 0.8 ± 0.2°C since 1870. It differs markedly between the two hemispheres, being more accentuated in the North and in the higher latitudes. Variability among continents is also observed. There has been a constant upward trend since 1870. According to NASA's Goddard Institute for Space Studies (GISS),1 the globally averaged combined land and ocean surface temperature data as calculated by a linear trend show a warming of 0.99 °C from 1880 to 2016.