A mini-ecosystem inside a bottle

Changes to environment and ecosystems: a climate change primer

Interested in climate change but not sure where to start? Our primer will help you understand the basics

Climate refers to the weather conditions that generally prevail in an area over a long period of time. These conditions include, but are not limited to, temperature, rainfall (precipitation) and humidity. Climate is a measure of patterns, and can be thought of as the average weather in one given location over 30 years or longer.

Changes within the normal range of weather defined by a climate – for example, an unusually cold winter, a wetter than average spring, a summer drought – are referred to as climate variability.

What we call climate change is a change in global or regional climate patterns, especially change caused by increased levels carbon dioxide in the atmosphere as a result of burning fossil fuels.

Climate change is being driven by the build-up of greenhouse gases in the atmosphere, mainly due to human activities.

Higher greenhouse gas levels are causing an enhanced greenhouse effect, leading to a global rise in temperature.

Higher temperatures are melting the icecaps and, with the thermal expansion of oceans, raising sea levels.

Significant changes to weather patterns are expected – more severe storms, more rain in wet areas, less rain in dry areas.

Other factors affect climates over differing timescales, including solar activity, ocean currents and other natural cycles. These factors are being swamped by the effects of greenhouse gases.

Climate changes are profoundly affecting the Earth’s environment and ecosystems. These effects are made worse by other forms of environmental degradation.

Lead image:

Pierre Pocs Photography/Flickr CC BY

About this resource

This resource was first published in ‘Health and Climate Change’ in January 2009 and reviewed and updated in September 2014.

Statistics and maths, Ecology and environment
Health and Climate Change
Education levels:
14–16, 16–19, Continuing professional development