When the United Nations’ Intergovernmental Panel on Climate Change (IPCC) released its landmark report in 2007, some people wondered if predictions of environmental changes might be too dire or unlikely to be seen in the current generation’s lifetime. This fall, a report compiled from research over the past three years warns us that the pace and scale of climate change may now be outstripping even the most sobering predictions of the earlier report.

Some events thought likely to occur over a longer time are already happening or set to happen far sooner than previously thought. Among those described in a news release from the UN are:

–Oceans are becoming more acidic more quickly than expected and impacting shellfish and coral reefs. Water that can corrode a shell-making substance is showing up along the California coast decades earlier than expected.

–Glaciers and ice sheets are melting faster than anticipated.

–Sea levels could rise by up to two meters (6.5 feet) by 2100.

–Tipping points in climate change may be reached in a few years.

Already, some irreversible impacts of climate change are damaging the environment: losses of mountain glaciers affecting drinking water, irrigation and hydropower; disappearing regional climates with losses of ecosystems, species; and the spread of drylands.

In a foreword to the document, the United Nations Secretary-General, Ban Ki-moon, says the Climate Change Science Compendium is “a wake-up call. The time for hesitation is over.” He adds, “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.”

The compendium is divided into five categories: earth systems, ice, oceans, ecosystems and management. Its release comes prior to the UN Climate Change Convention that will be held in Copenhagen on December 7-18.