Countries around the world are pledging to cut their carbon emissions ahead of next month’s highly anticipated climate summit in Paris, part of a desperate coordinated effort to stave off the catastrophic effects of global warming and climate change. But even if these promises are kept, they won’t go nearly far enough, according to a new analysis released Friday by the United Nations Environment Programme.
In its sixth annual “Emissions Gap” report, the UNEP analyzed pledges submitted by nearly 150 countries, which collectively contributed more than 85 percent of total global greenhouse gas emissions in 2012. The report found that the pledges would amount to only about half of the greenhouse gas emission cuts needed to stabilize warming below dangerous levels by the end of the century.
“We are beginning to bend the curve, but … it is not yet enough,” said UNEP Executive Director Achim Steiner. “It is probably halfway toward what we do need to achieve on a longer term trajectory.”
The Paris climate meeting will take place between Nov. 30 and Dec. 11, and attendees are tasked with shaping the first-ever universal climate pact. Forming the backbone of that pact are these emissions-reduction pledges, known as Intended Nationally Determined Contributions (INDCs).
The United States, one of the nations that contributes the most to global warming, has pledged to reduce its greenhouse gas emissions by slightly more than one-quarter (relative to 2005 levels) by 2025, the report says. China has committed to lowering carbon dioxide emissions “per unit of GDP by 60% to 65%.” Meanwhile, poorer nations that contribute very little to global emissions but face some of the biggest threats from climate change have made promises as well. The Maldives, an island chain and one of the countries most threatened by rising sea levels, emits just 0.003 percent of the world’s greenhouse gases, yet promises a 10 percent reduction in emissions — up to 24 percent if it gets international assistance.
While the pledges represent a “historic step,” Steiner said in a statement, they “are not sufficient to limit global temperature rise to the recommended level of 2 degrees Celsius (3.6 degrees Fahrenheit) this century.”
Current targets to slow global warming are ‘utterly inadequate’
Scientists have warned that a rise in global temperatures beyond 2 degrees Celsius would trigger the most devastating effects of climate change, such as intolerable drought, mass migration and superstorms. With mounting evidence that climate change is happening much faster than previously thought and resulting in more severe consequences, a growing number of experts have suggested limiting the rise to less than 1.5 degrees, since even that level of warming is projected to bring dire outcomes, especially to poorer nations.
In an article published earlier this year, Dr. Petra Tschakert, a Penn State professor and the coordinating lead author for the Intergovernmental Panel on Climate Change, assailed the 2-degree limit as “utterly inadequate,” citing evidence that most of the world’s coral reefs would perish and sea levels would rise more than three feet after a 2-degree increase. Still other research puts forth even more dire predictions. In 2015 analysis of global ocean temperatures, researchers identified a new feedback mechanism off the coast of Antarctica that was dramatically increasing the melting rate of glaciers, resulting in much more rapid sea-level rise. The study—conducted by James Hansen, NASA’s former head climate scientist, and 16 co-investigators including many of the top scientists across a variety of fields—concluded that glaciers in Greenland and Antarctica are melting at a rate 10 times faster than previously predicted, and could lead to a rise in sea level of at least 10 feet in as little as 50 years. The authors included this chilling warning:
If emissions aren’t cut immediately, “We conclude that multi-meter sea-level rise would become practically unavoidable. Social disruption and economic consequences of such large sea-level rise could be devastating. It is not difficult to imagine that conflicts arising from forced migrations and economic collapse might make the planet ungovernable, threatening the fabric of civilization.”
Moreover, the temperature rises associated with anthropogenic (human-induced) climate change are not uniform across the globe, nor is vulnerability to these changes. Therefore the difference in projected risks between 1.5 degrees Celsius and 2 degrees Celsius of warming is particularly important for highly temperature-sensitive systems, such as the polar regions, high mountains and the tropics, and low-lying coastal regions. As Archbishop Desmond Tutu argued at the 2009 Copenhagen climate conference, a 2-degree global mean temperature rise could result in Africa’s temperature rising as much as 3.5 degrees—a potentially disastrous change that would bring on sustained drought, massive reductions in crop yield, and subsequent famine.
Based on mounting evidence that the 2-degree target is “inadequate and unsafe,” scientists concluded in the most recent report from the Intergovernmental Panel on Climate Change (IPCC) that countries should aim to limit average global temperature rises to no more than 1.5 degrees by the end of the century. As of October, over 100 countries and hundreds of civil society groups had joined together to urge world leaders to agree on a 1.5-degree target at the Paris climate talks. However, the 2-degree target is the choice of wealthy nations, for the most part, because the increased heat and sea levels won’t affect them as quickly or severely, and developing nations like India and China, as well as oil-producing states like Saudi Arabia, have successfully blocked efforts at the climate negotiations to bring down the temperature limit to 1.5 degrees or less.
Adding it up: The frightening math of carbon emissions
To put things into perspective, a U.N. report released earlier this year found that climate change now accounts for 87% of deadly natural disasters worldwide — and that’s with only a global temperature rise of 0.8 degrees Celsius since the pre-industrial era. In the best case scenario — the 2-degree goal adopted by nearly 150 U.N. member states — the world is looking at more-than doubling that temperature rise by the end of the century. But even if all nations follow through on their current pledges to reduce emissions, the UNEP estimates in its new report that global temperatures will still be on track to jump at least three degrees Celsius (4.8 degrees Fahrenheit) by 2100.
To stay within the 2-degree limit, global emissions levels should not exceed 42 billion metric tons in 2030, according to the U.N.’s climate science panel. Without the INDCs, humanity is set to spew some 60 billion metric tons of carbon dioxide equivalent — a measure that groups different greenhouse gases including methane and nitrous oxide — into the atmosphere in 2030. The INDCs would shave 6 billion metric tons off the top, leaving the total at 54 billion metric tons. That means that the INDCs only cover one-third of the 18 metric ton gap between the current trajectory, and where we need to be in 2030.
“The submitted contributions are far from enough, and the emissions gap in both 2025 and 2030 will be very significant,” the UNEP report says. Moreover, it notes, greenhouse gas output would still be rising in 2030. Many scientists say it is crucial to bend the emissions curve — to make it peak, in other words — as soon as possible. The longer we wait, they say, the harder and more expensive it will be to transition to a low-carbon global economy.
In 2014, greenhouse gas emissions from all sources totaled just under the equivalent of 53 billion metric tons of CO2. That output will have to drop to near zero by 2075 at the latest to stay under the 2-degree limit, scientists say. Scientists are already investigating an assortment of extreme measures, such as sucking massive amounts of carbon dioxide out of the atmosphere, but it’s unlikely these will be ready for use anytime soon.
The UNEP findings bolster a report released last week by the UN’s climate body showing that — even if all of these national carbon-cutting schemes are actually carried out — humanity will have exhausted 75 percent of its total “carbon budget” by 2030.
Besides mitigating and preventing the worst effects of global warming, experts say reducing carbon emissions will boost health in two main ways: First, by slowing climate change, and thereby reducing the number of extreme weather events like hurricanes, floods and heat waves, which can lead to problems like shortages or contamination of water and food supplies, heat stroke and deaths, as well as further spread of infectious diseases. Secondly, by boosting air quality, known as a “co-benefit,” there would be fewer premature deaths, heart attacks, asthma, and stroke.