Scientists have been recording temperatures for hundreds of years using thermometers. These can measure air temperature on land or sea surface temperature in the oceans. Before digital thermometers, scientists wrote readings in weather logs and charts, creating a long record of how Earth’s temperature has changed over time.

• Thermometers measure temperature in degrees Celsius (°C) or Fahrenheit (°F).

• Modern thermometers use digital sensors that automatically record data every few minutes or hours.

• These readings are stored in global databases like NASA and the UK Met Office.

• Scientists compare new data to old records to spot patterns and trends.

Facts:

• Average global temperature has risen by about 1.1°C since the late 1800s.

• Some areas are warming faster than others for example, the UAE is seeing more hot days each year.

• Temperature data helps scientists link climate change to heatwaves, droughts, and extreme weather.

Ocean buoys are floating devices anchored or drifting in the sea. They collect information about the ocean’s temperature, salt levels (salinity), currents, and wave height. Thousands of buoys around the world send data to scientists every hour via satellite.

• Each buoy has sensors below the surface to measure water temperature and salinity.

• Some also measure carbon dioxide levels or oxygen in the water.

• The information is transmitted to research centers on land in real time.

• Scientists use this data to create maps showing how oceans are warming and changing.

Facts:

• Oceans absorb over 90% of the extra heat trapped by greenhouse gases.

• Rising ocean temperatures cause coral bleaching, melting sea ice, and stronger tropical storms.

• Salinity data helps track melting glaciers, since melting ice makes seawater less salty.

Satellites orbit Earth high above the atmosphere and take pictures or measure energy from the planet’s surface. They collect information about temperature, ice cover, forest growth, clouds, air pollution, and sea levels.

• Satellites use sensors and cameras to observe Earth’s surface, atmosphere, and oceans.

• Some measure infrared radiation to detect temperature changes.

• Data is sent back to Earth and turned into maps and animations showing how the planet is changing.

• Different satellites focus on different aspects — e.g. NASA’s Aqua and Terra satellites track global temperatures and cloud patterns.

Facts:

• Shows how ice caps and glaciers are shrinking.

• Monitors sea level rise and coastal flooding risks.

• Tracks deforestation, urban growth, and air pollution.

• Provides global, continuous data to compare regions and time periods.