Carbon dioxide emissions need to be limited.
However, the potential carbon dioxide emissions contained in fossil fuel reserves are vast.
So it's not possible for all current fossil fuel reserves to be used, if the Earth's warming is to be kept below 2 °C.
This huge excess quantity of fossil fuel is sometimes called the 'Carbon Bubble'.
Research that investigated what would happen if all the fossil fuels are burned has come to some worrying conclusions:
“Burning all fossil fuels” would warm land areas on average about 20°C (36°F) and warm the poles a stunning 30°C (54°F).
This “would make most of the planet uninhabitable by humans, thus calling into question strategies that emphasize adaptation to climate change.”
Calculated warming over land areas averages approximately 20°C.
Such temperatures would eliminate grain production in almost all agricultural regions in the world.
Researchers say that higher temperatures could significantly reduce yields of wheat, rice and maize – dietary staples for tens of millions of poor people who subsist on less than $1 a day.However, there are major objections even to the "two-degree limit".
Many say the number is simply too high.
Archbishop Desmond Tutu has pointed out that a two-degree global average rise might result in Africa’s temperature rising as much as 3.5 degrees—a potentially disastrous change.
Various scientific research projects have looked at what would happen if all the fossil fuels were burned.
One project concluded:
... burning the currently attainable fossil fuel resources is sufficient to eliminate the ice sheet.