U.N. report on global warming carries life-or-death warning but pessimists doubt the likelihood of change.
Climate change is a change in the statistical distribution of weather patterns when that change lasts for an extended period of time. Global warming is the observed century-scale rise in the average temperature of the Earth's climate system and its related effects. Multiple studies published in peer-reviewed scientific journals show climate-warming trends over the past century are likely due to human activities. In addition, most of the leading scientific organizations worldwide have issued public statements endorsing this position.
Climate change poses a fundamental threat to the places, species and people’s livelihoods. Sea levels are rising and oceans are becoming warmer. Longer, more intense droughts threaten crops, wildlife and freshwater supplies. From polar bears in the Arctic to marine turtles off the coast of Africa, our planet’s diversity of life is at risk from the changing climate.
The Nobel Prize-winning Intergovernmental Panel on Climate Change issued its gloomy report at a meeting in Incheon, South Korea, highlighting a global climate crisis.
In the 728-page document, the U.N. organization detailed how Earth’s weather, health and ecosystems would be in better shape if the world’s leaders could somehow limit future human-caused warming to just 0.9 degrees Fahrenheit (a half degree Celsius) from now, instead of the globally agreed-upon goal of 1.8 degrees F (1-degree C)
Limiting warming to 0.9 degrees from now means the world can keep “a semblance” of the ecosystems we have. Adding another 0.9 degrees on top of that — the looser global goal — essentially means a different and more challenging Earth for people and species, said another of the report’s lead authors, Ove Hoegh-Guldberg, director of the Global Change Institute at the University of Queensland, Australia.
However, reaching the more ambitious goal of slightly less warming would require immediate, draconian cuts in emissions of heat-trapping gases and dramatic changes in the energy field. While the U.N. panel says technically that’s possible, it saw little chance of the needed adjustments happening.
In 2010, international negotiators adopted a goal of limiting warming to 2 degrees C (3.6 degrees F) since pre-industrial times. It’s called the 2-degree goal. In 2015, when the nations of the world agreed to the historic Paris climate agreement, they set dual goals: 2 degrees C and a more demanding target of 1.5 degrees C from pre-industrial times. The 1.5 was at the urging of vulnerable countries that called 2 degrees a death sentence.
The world has already warmed 1-degree C since pre-industrial times, so the talk is really about the difference of another half-degree C or 0.9 degrees F from now.
“There is no definitive way to limit global temperature rise to 1.5 above pre-industrial levels,” the U.N.-requested report said. More than 90 scientists wrote the report, which is based on more than 6,000 peer reviews.
“Global warming is likely to reach 1.5 degrees C between 2030 and 2052 if it continues to increase at the current rate,” the report states.
Deep in the report, scientists say less than 2 per cent of 529 of their calculated possible future scenarios kept warming below the 1.5 goals without the temperature going above that and somehow coming back down in the future.
The pledges nations made in the Paris agreement in 2015 are “clearly insufficient to limit warming to 1.5 in any way,” one of the study’s lead authors, Joerj Roeglj of the Imperial College in London, said. Yet the report authors said they remain optimistic.
To limit warming to the lower temperature goal, the world needs “rapid and far-reaching” changes in energy systems, land use, city and industrial design, transportation and building use, the report said. Annual carbon dioxide pollution levels that are still rising now would have to drop by about half by 2030 and then be near zero by 2050.
Emissions of other greenhouse gases, such as methane, also will have to drop. Switching away rapidly from fossil fuels like coal, oil and gas to do this could be three to four times more expensive than the less ambitious goal, but it would clean the air of other pollutants. And that would have the side benefit of avoiding more than 100 million premature deaths through this century, the report said.
Our assessment is that now more than ever, the international community must commit itself to the Paris Agreement to ensure global temperatures do not rise exponentially. Climate change is an existential threat to mankind. We believe that If climate change is not addressed, it could result in a massive loss of biodiversity and loss of life.