The majority of climate researchers believe that the main
cause of the rapidly changing climate, especially since 1975, is our
fossil fuel-burning activities, which
increase the amount of carbon dioxide and other “greenhouse gases” in the
atmosphere – these act like a giant blanket causing global warming.
Although burning of coal, oil and gas is the
main contributor, other causes of greenhouse gas emissions include:
deforestation, decaying material in landfill sites, cement and pesticide
manufacture, growth of farm animals, rice production in wet conditions. The rapidly increasing
world population adds to the scale of all these things.
Since pre-industrial times, we have added
around one-third more carbon dioxide to the atmosphere and doubled the
methane, plus nitrous oxide and a range of industrial gases. These emissions are nowadays
accurately measured (e.g. 26% more atmospheric CO2 since 1958) and are rapidly increasing.
The warming is believed to put more energy
into the climate systems
and to result in an increase in the severity and frequency of extreme weather events: floods, droughts, storms, wildfires and
extreme temperatures; giving rise to growing hunger, homelessness,
disease, injury, loss of life and livelihood.
Although there is no hard proof that our
emissions are the major cause of climate change (and may never be), the
frequent record-breaking temperatures, and regularity of severe flooding,
droughts and wildfires in different countries fit the expected trend of more
The main risk is that, as global warming
increases (irreversibly), the point will be reached where the world climate
could de-stabilise, causing a rapid uncontrollable acceleration -
"runaway warming" with catastrophic spiralling effects.