Icecaps in Antarctica


Weather vs Climate

The main difference between weather and climate is that they each refer to a different timescale. Weather describes the conditions of the atmosphere over hourly or daily measurements such as temperature, rainfall, cloudiness, sunshine, and wind speeds. Climate, on the other hand, is the average of these conditions over longer time periods ranging from years to decades.

In the words of Robert Heinlein, "Climate is what you expect, weather is what you get". Perhaps even more simply, "Weather is how you choose your outfit, climate is how you choose your wardrobe".

Video on the climate

Click the ‘Climate’ link below to learn more about climate observations, climate zones, and the factors that affect our global climate.

What is climate change?

Whilst there is natural variability in both weather and climate, 'climate change' refers to systematic, large-scale, long-term shift in the planet’s weather patterns and average temperatures. These changes can be in response to natural factors (e.g. a volcanic eruption or changes in solar activity) or a result of human activities (e.g. emissions of greenhouse gases from industry or changes in land use).

Since the last ice age which ended about 11,000 years ago, the Earth's climate has been relatively stable with an average global temperature of about 14 °C. However, global temperatures have risen significantly over the 20th and 21st centuries, causing a range of impacts such as changes to rainfall patterns, rising sea levels, and seasonal changes. There is overwhelming and growing evidence that the change in climate over this time period is due to vastly increased, and still increasing, quantities of greenhouse gas in the atmosphere. In fact, since the Industrial Revolution, atmospheric CO2 has increased by over 40% to levels that are unprecedented in at least 800,000 years.