How can we be sure that global warming is happening and that we are responsible?

The IPCC 4th Assessment Report (2007) - drawn from research of over 2000 scientists and endorsed by 130 governments - reports that temperature rises are UNEQUIVOCAL.

The IPCC can now say with 90% certainty that human activities are responsible for higher concentrations of CO2 (the highest in 650,000 years) and other Greenhouse gases (ghg) in the atmosphere, and hence the corresponding overall warming of the climate. Human activities primarily attributed to this are fossil fuel use, land use change and agriculture.

How much have temperatures increased since the pre-industrial era?

The climate is 0.76°C warmer than in pre-industrial times (pre-1850). Some scientists report a 0.5°C rise in temperatures in the last 30 years.

11 of the 12 warmest years recorded since 1850 have occurred in the last 12 years.

If we don't change our emitting habits, how much will temperatures rise by 2100?

If CO2 concentrations remain at current levels or increase, we could see rises in temperature of anything between at least 1.8 - 4°C by 2100.

What minimum rise in global temperatures can the planet and humans realistically sustain?

A 2º C rise in global mean temperatures over 1990 levels has for some time been recognized as a dangerous ‘tipping’ point that would unleash almost certain ‘runaway’ climate change on a global and horrifically destructive scale.

A 6 ºC rise in global temperatures has been credited with causing a mass extinction of at least 90 percent of life on Earth about 250 million years ago. The cause of such massive releases of greenhouse gases has been put down to volcanic eruptions sustained over a period of half a million years.

How much do we have to reduce emissions to safeguard the future of our planet?

In order to keep global warming below 2 degrees, ghg emissions must be reduced to 80 percent of 1990 levels by 2050.

Currently we could be on track to see global emissions doubling by 2050.

Which regions will be most affected by climate change?

Africa is likely to face the worst impacts, through a combination of affects on the climate, and the vulnerability of people living in Sub-Saharan Africa – reliance on agriculture, dependence on weather, and a lower capacity to respond.

Higher latitudes will experience greater warming. Northern and central Asia are likely to heat up 40% more than other parts of Asia. The link between high temperatures and increasing mortality rates is already known. An intense heat wave in India in May 2002 led to the loss of 1000 lives.

Will climate change affect people’s access to food?

Changes in rainfalls and temperatures as well as increasing occurrences of extreme weather events will change the food production potential in many parts of the world. In countries where most of the population is reliant on the food they produce themselves, this could have devastating consequences.

Two thirds of the poorest people of the world live in rural areas and rely on agriculture for their livelihood. Around 850 million people are currently at risk of hunger.

What impacts will climate change have on poor people’s health?

182 million people in sub-Saharan Africa alone could die of diseases directly attributable to climate change by the end of the century.

The WHO estimates that climate change is already responsible for over 150,000 deaths each year. This is through an increase in cases of diarrhoea, malaria and malnutrition, predominantly in developing countries.

A rise of 2-3°C will lead to water scarcity for 2 billion people.