...the newly emerging science points to some events thought likely to occur in longer-term time horizons, as already happening or set to happen far sooner than had previously been thought.
Pressing concerns include "ocean acidification linked with the absorption of carbon dioxide in seawater and the impact on shellfish and coral reefs" (happening decades earlier than existing models predict, and melting glaciers, ice-sheets and the Polar Regions (example: the Greenland ice sheet is melting 60 percent higher than the previous record of 1998), which can cause sea levels to rise by up to two metres by 2100 and five to ten times that over following centuries. The report says "thresholds or tipping points may now be reached in a matter of years or a few decades including dramatic changes to the Indian sub-continent's monsoon, the Sahara and West Africa monsoons, and climate systems affecting a critical ecosystem like the Amazon rainforest."
Damaging and irreversible impacts as a result of the greenhouse gases already in the atmosphere include:
- Losses of tropical and temperate mountain glaciers affecting perhaps 20 percent to 25 percent of the human population in terms of drinking water, irrigation and hydro-power.
- Shifts in the hydrological cycle resulting in the disappearance of regional climates with related losses of ecosystems, species and the spread of drylands northwards and southwards away from the equator.
The good news is there is hope:
Recent science suggests that it may still be possible to avoid the most catastrophic impacts of climate change. However, this will only happen if there is immediate, cohesive and decisive action to both cut emissions and assist vulnerable countries adapt.
United Nations Secretary-General, Ban Ki-moon, says: "This Climate Change Science Compendium is a wake-up call. The time for hesitation is over. We need the world to realize, once and for all, that the time to act is now and we must work together to address this monumental challenge. This is the moral challenge of our generation."
See Impacts of Climate Change coming faster and sooner: New science report underlines urgency for governments to seal the deal in Copenhagen. Click here for the full UNEP report.