Summary
Climate change is heating our oceans. This is causing stronger hurricanes, sea level rise, and the death of sea life. Warmer oceans also absorb less carbon making every ton of CO2 we emit more potent for the planet.
This visualization keeps close tabs on rising global ocean temperatures. It is updated daily.
The data
This visualization shows daily global sea surface temperature compared to historical temperatures before humans started emitting greenhouse gases in large quantities. Here’s how it works:
This chart shows, for each day, how much Earth's sea surface average temperature differs from pre-industrial times (1850-1900). We use this historical baseline to clearly show warming relative to global climate targets like the 1.5°C threshold established in the Paris Agreement.
The data covers the oceans from 60° South to 60° North latitude, and all longitudes and is updated daily, with a 5-6 day delay due to data processing times. Specifically, the metric displayed is the temperature right at the surface of the oceans.
The temperatures come from ERA5, which is the fifth generation ECMWF (European Centre for Medium-Range Weather Forecasts) reanalysis dataset. ERA5 combines actual observations with physics-based models to create a complete picture of global climate.
Each day's global temperature is calculated by:
- Taking measurements eight times throughout the day (at midnight, 3am, 6am, 9am, noon, 3pm, 6pm, and 9pm UTC)
- Applying a weighted average that accounts for the fact that gridcells are not all equal in size (grid squares near the poles cover less actual area than squares near the equator)
- Averaging these readings to get a daily value
- Comparing this to the pre-industrial baseline using the 0.88°C adjustment value cited in the IPCC AR6 report, Chapter 9.
Citation
Copernicus Climate Change Service (C3S) (2023): ERA5 hourly data on single levels from 1940 to present. Copernicus Climate Change Service (C3S) Climate Data Store (CDS). 10.24381/cds.adbb2d47.
