Evidence of Climate Change

Surface Temperature
Land Ocean Land and Ocean

Surface temperature over the land and ocean temperature is rising across the globe. These plots show land, ocean, and merged land and ocean surface temperature (radio buttons) for both the Nothern Hemisphere and the globe (tabs).

This temperature reconstruction dates back to 1880, and is typically current through the last month. The solid red line is the yearly temperature average, and the shaded pink area illustrates the potential uncertainty associated with the data.
Data source: NOAA MLOST.

Sea Ice

Arctic sea ice has been declining since satellite measurements began in 1979, continuing the long-term decline that began in the 1950s. Sea ice reaches its minimum extent in September in the Arctic. Both Arctic and Antarctic sea ice is shown here (tabs) for all months (drop-down list).

Sea ice extent measurements are made with satellite instruments, and are given in millions of square kilometers. Sea ice measurements are available within the satellite era, and are shown here from 1979 through the previous month. Data source: National Snow and Ice Data Center.

Carbon Dioxide
in thousands of years ago

CO2 is an important greenhouse gas that is emitted naturally and by human activities. The Mauna Loa Observatory, which resides on the Mauna Loa volcano in Hawaii, has been collecting CO2 data since 1956 (in yellow). The CO2 reconstruction (orange) begins 650,000 years ago, when CO2 concentration was around 225 ppm, and ends with the Mauna Loa record, which is approaching 400 ppm. CO2 is measured in parts per million (ppm). Click on the small graph to make it large. Data source: NOAA.

in thousands of years ago
Sea Level

Sea level rise is primarily caused by thermal expansion (water expands when it's warmed), and the melting of land ice, which runs off into the ocean. The data shown above were collected using satellite instruments designed to measure the height of sea level. Sea level is shown here in centimeters from January of 1993 to the end of the previous year. Data source: CLS/Cnes/Legos.