Climate is not the same as weather. It is long term, whereas weather is short term, like today, or this week.
Climate is a large, complex system which, like any system, can be affected by different things. By pushing more greenhouse gases into the atmosphere and so trapping heat which would otherwise escape into space, by doing this, we are pushing more energy into the system, and our climate produces weather patterns according to how much energy is in the system. This disturbs weather patterns, meaning we get hotter, drier, wetter, windier weather in different places at different times to usual.
The more greenhouse gases, the more the climate and the weather are affected. Human systems rely on the stability of natural systems in order for civilisation to function. To grow food, for one thing. When we disturb the climate and the weather, we risk disturbing our ability to eat.
Greenhouse gases can be both natural and man-made, and include carbon dioxide (CO2), methane, nitrous oxide, water vapour and hydrofluorocarbons (HFCs). They can be released in various ways, either through industrial or natural processes.
Land-use change, such as deforestation, is a big contributor because trees are essentially ‘wet sticks of carbon’, and so burning them both releases CO2 and prevents the trees from absorbing CO2 through photosynthesis, their method of turning sunlight, nutrients and water into energy to grow.
Burning fossil fuels for energy – coal, oil and gas – is a major contributor, as is industrial agriculture, from use of carbon-based pesticides and fertilisers, and fuel for tractors etc. These inputs are avoided in organic agriculture.
So, many human processes increase the amount of greenhouse gases discharged into the atmosphere, and many others remove the earth’s natural ability to absorb them.
This double process is further increased and accelerated by ‘positive feedbacks’ in nature, such as in the Arctic. Here, the loss of ice and snow also removes its ability to reflect heat. Absorbing heat means more melting, which means more heat is absorbed and so on. There are many more examples of this, from deforestation in the tropics especially, to the release of methane in peat bogs. All of these things are happening today, and accelerating.
The solution is to increase the earth’s capacity to absorb and store carbon. This is called biological carbon sequestration, or biosequestration. It can be done through forest protection, reforestation and use of biochar on land, and enhancement of carbon-absorbing plants such as seagrasses in marine ecosystems.
Arguments over climate change being man-made or otherwise are not as complex as they seem.
Those who wish there to be no change to the way humans do things (fossil fuel industry especially) are usually those who would lose out financially, and also happen to be wealthy and politically influential.
Therefore, they employ FUD – fear, uncertainty and doubt, the same tactics that the cigarette industry always used. They famously said “doubt is our product.”
United Nations Framework Convention on Climate Change Reports:
Fact sheet: 10 frequently asked questions about the Copenhagen deal
Fact sheet: Copenhagen – Background information
Fact sheet: The Kyoto Protocol
Fact sheet: Why technology is so important