A United Nations panel today said that the effects of climate change are already being felt across the globe, warning in a major report that they will likely be "severe, pervasive, and irreversible" in the years to come. The report, released by the UN's Intergovernmental Panel on Climate Change (IPCC), concludes that rising global temperatures are already having clear impacts on agriculture, human health, and water supplies across all continents, oceans, and ecosystems.

These effects will become more severe over time, the panel added, putting food supplies, infrastructure, and economies at serious risk. The IPCC noted that poor countries would be especially hard hit, due to lower crop yields and tighter water supplies, though it cautioned that all will feel the effects of climate change going forward.

"Nobody on this planet is going to be untouched."

"Nobody on this planet is going to be untouched by the impacts of climate change," IPCC Chairman Rajendra Pachauri told reporters today.

The report released in Japan today was based on more than 1,200 peer-reviewed studies, and is the second in a series of three that the IPCC will release this year. In a similarly comprehensive report released last year, the IPCC determined that humans are almost certainly to blame for rising global temperatures, calling for policymakers to take greater steps to contain greenhouse gas emissions. The IPCC's findings will likely play a major role in international discussions on combatting climate change next year.

"Unless we act dramatically and quickly, science tells us our climate and our way of life are literally in jeopardy," US Secretary of State John Kerry said in a statement following the report's release. "Denial of the science is malpractice," he added.

On Monday, the panel said that changing precipitation patterns and melting ice are already shifting water systems, and that many fish species are moving to new waters or going extinct. Rising ocean levels are threatening coastal communities, while melting permafrost in the Arctic is releasing centuries-old organic matter that will decay and release even more greenhouse gases, the report notes. According to the IPCC, the amount of scientific evidence of the effects of climate change have nearly doubled since 2007.

A call for "bolder, more ambitious" action

These effects are likely to be more acute in the future, and could lead to widespread health problems and violent conflicts over land and resources. The IPCC notes that many countries have already begun adapting to climate change, though it called upon governments and businesses to invest more to mitigate the serious risks it foresees.

"Governments, firms, and communities around the world are building experience with adaptation," Chris Field, co-chair of the IPCC Working Group II, said in a statement. "This experience forms a starting point for bolder, more ambitious adaptations that will be important as climate and society continue to change."