In 2015, the Paris climate agreement saw 195 countries agree to keep the average global temperature from rising above 2 degrees Celsius than the average prior to the industrial revolution.
Three years later, a report released from the Intergovernmental Panel on Climate Change (IPCC) on 8 October 2018 found that the world is on track to see temperatures reach 1.5 degrees higher than preindustrial levels by as soon as 2040. This will bring severe environmental changes, the report found, despite the lower threshold.
Conducted at the behest of island nations who believed that dangerous effects of climate change would be felt before reaching the 2-degree mark, the report confirmed that if greenhouse gas emissions continue to rise at their current rate, much of the globe’s current population will be left to negotiate worsening droughts, fires, famine, sea-level rise and desertification sooner than previously thought.
Already, the world is 1 degree warmer than preindustrial times, which has contributed to catastrophes such as tropical peatland fires and the intensifying of North American hurricanes. “Rapid” and “unprecedented” changes in all aspects of society are required to cap warming at 1.5 degrees, says the report, which was written and edited by more than 91 scientists from 40 countries and its conclusions drawn from more than 6,000 scientific studies.
To achieve this, human-caused emissions of carbon dioxide need to fall by 45 percent of their 2010 levels by 2030. By 2050, these emissions will need to have dropped far enough to be net-zero with the removal of carbon dioxide from the air.
The report pointed to a massive reduction of coal as imperative to achieving these reductions. A substantial carbon tax of up to USD 5,500 per ton of carbon dioxide pollution by 2030 could buoy efforts.
The differences in the impacts of the climate changing 2 versus 1.5 degrees are considerable, including the loss certain ecosystems and species (high-latitude tundra and boreal forests are at particular risk); a more drastic rise in ocean temperature and acidification, killing some 99 percent of coral reefs and affecting fisheries; a 50 percent increase in the global population exposed to water stress; the death of insects crucial to food security; and ice-free summers in the Arctic.
The IPCC is tasked by the United Nations to produce reports such as these to guide world leaders and policymakers on climate change mitigation and adaptation. The release of this report – presented in Incheon, South Korea – comes at a politically tumultuous time, with President Donald Trump having promised to withdraw from the Paris agreement, and the ongoing presidential election in Brazil appearing to be in favor of Jair Bolsonaro, who has also said he plans to withdraw.
The next few years are the most important in human history, said Debra Roberts, Co-Chair of the IPCC working group focused on impacts, and leaders must use this information to alter this course of radical adverse change.
Nevertheless, delegates at the presentation remained hopeful. “The good news is that some of the kinds of actions that would be needed to limit global warming to 1.5 degrees are already underway around the world,” said Valerie Masson-Delmotte, Co-Chair of the working group on the physical scientific basis of climate change, “but they would need to accelerate.”