What makes climates

These winds converge in the tropics, forcing air to rise. This produces thunderstorms, humidity, and monsoons. Also, dry air is sinking back to the surface, warming in the process. This is why many of the world's great desert regions—the Sahara, Gulf, Iran, Iraq, and chunks of Mexico—lie at the same latitude. A similar band of deserts lies to the south in Australia, South America, and southern Africa. Mountains force wind to rise as it crosses over them.

This cools the air, causing moisture to condense in clouds and rain. This produces a wet climate on the upwind side of the mountains and an arid "rain shadow" on the downwind side.

Oceans provide moisture that fuels rainstorms. They also buffer the temperature of coastal regions, regardless of latitude. Moist, tropical climates are hot and humid. Steppes and deserts are dry, with large temperature variations. Plentiful lakes, rivers, or nearby oceans give humid, midlatitude climates cool, damp winters, but they have hot, dry summers. Some of these climates are also called Mediterranean. Continental climates occur in the centers of large continents. Mountain ranges or sheer distance block off sources of moisture, creating dry regions with large seasonal variations in temperature.

Much of southern Canada, Russia, and parts of central Asia would fall into this category. A sixth region, high elevations, was later added to the classification system. A supercell thunderstorm strikes in South Dakota. Among the most severe storms, supercells can bring strong winds, hail, and even tornadoes.

See more extreme weather pictures. All rights reserved. Lightning Strikes A supercell thunderstorm strikes in South Dakota. The Earth wobbles on its axis, much like a spinning top that is slowing down. This means that the North Pole changes where it points to in the sky. It impacts on the seasonal contrasts between hemispheres and the timing of the seasons. Greenhouse gases include carbon dioxide CO 2 , methane CH 4 and water vapour. Water vapour is the most abundant greenhouse gas in the atmosphere, but it stays in the atmosphere for a much shorter period of time: just a few days.

CH 4 stays in the atmosphere for about nine years until it is removed by oxidation into CO 2 and water. CO 2 stays in the atmosphere much longer, from years to centuries, contributing to longer periods of warming. Ocean currents carry heat around the Earth. As the oceans absorb more heat from the atmosphere, sea surface temperature increases and the ocean circulation patterns that transport warm and cold water around the globe change.

The direction of these currents can shift so that different areas become warmer or cooler. As oceans store a large amount of heat, even small changes in ocean currents can have a large effect on global climate. In particular, increases in sea surface temperature can increase the amount of atmospheric water vapour over the oceans, increasing the quantity of greenhouse gas.

CO 2 content of the oceans. Over very long periods of time, plate tectonic processes cause continents to move to different positions on the Earth. For example, Britain was near to the equator during the Carboniferous Period, around million years ago, and the climate was warmer than it is today.

The movement of the plates also causes volcanoes and mountains to form and these can also contribute to a change in climate. Large mountain chains can influence the circulation of air around the globe, and consequently influence the climate.

For example, warm air may be deflected to cooler regions by mountains. During major explosive volcanic eruptions , large amounts of volcanic gas, aerosol droplets and ash are released. Ash falls rapidly, over periods of days and weeks, and has little long-term impact on climate change. However, volcanic gases that are ejected into the stratosphere stay there for much longer periods. Volcanic gases such as sulphur dioxide SO 2 can cause global cooling, but CO 2 has the potential to cause global warming.

In the present day, the contribution of volcanic emissions of CO 2 into the atmosphere is very small; equivalent to about one per cent of anthropogenic caused by humans emissions. On a global scale, patterns of vegetation and climate are closely correlated. Vegetation absorbs CO 2 and this can buffer some of the effects of global warming.

On the other hand, desertification amplifies global warming through the release of CO 2 because of the decrease in vegetation cover. This has huge implications for our livelihoods and human security. Fragile ecosystems, like coral reefs, are also already succumbing to climate change impacts.

Melting glaciers, rising sea levels, and new and more frequent weather extremes will leave no continent untouched. If we let the warming continue unchecked, we run a real risk of hitting catastrophic tipping points. That's where the warming triggers positive feedback loops that lead to even more warming. To avoid the worst impacts of climate change, scientists warn that average global temperatures should not be allowed to rise more than 1. When the world's governments committed to the Paris Agreement in - a new, global deal on climate change - they answered a call from our Pasifika neighbours, and agreed to try to keep warming below 1.

A rise in temperature above 1. Thing is, this won't just stop climate change. Switching from dirty fossil fuels to clean renewable energy will be better for people, communities and businesses all over the world. And the change is already underway. Renewable energy technologies like wind and solar are getting cheaper and cheaper, and rolling out worldwide faster and faster.

We can do this. Causes of climate change Climate change is happening because of us. This climate change is because of human activity The main causes of climate change are:. Leonardo DiCaprio. We don't know where the tipping points are The thing is, temperature rise won't be linear. But we have the solutions The good news is: we have the solutions.

Read more. Taking climate action New Zealand impacts Global impacts Why 1.