The stark escalation of human-induced global warming from greenhouse gas emissions, progressing at a “unprecedented rate,” has echoed a pressing alarm, as declared by 50 preeminent scientists. They report that the increase in the global temperature is an immediate result of human activities, and it is surging faster than previously anticipated.
Their timely revelation, a “wake-up call,” comes at a critical juncture as climate experts convene in Bonn. Their meeting is the prelude to the major COP28 climate conference in UAE, slated for December. The conference will assess global efforts to keep the temperature increase below 1.5°C by 2050.
However, the swift pace of climatic changes makes access to robust scientific evidence crucial for informed decisions. Policymakers, climate negotiators, and civil society groups need this data to effectively respond to the climate crisis.
The UN’s Intergovernmental Panel on Climate Change (IPCC) is recognized as a reliable source of scientific information. However, their major assessments typically take five to ten years to complete, creating a critical “information gap” during this rapidly changing climate scenario.
To bridge this gap, scientists from the University of Leeds have launched a novel open-data, open-science platform — the Indicators of Global Climate Change (IGCC). This online resource, available at https://igcc.earth/, will provide annual updates on key climate indicators and greenhouse gas emissions.
Professor Piers Forster, the coordinator of the project and Director of the Priestley Centre for Climate Futures at Leeds, emphasizes the importance of this decade for climate change. He states, “Decisions made now will have an impact on how much temperatures will rise and the degree and severity of impacts we will see as a result.”
According to Professor Forster, there is already evidence that greenhouse gas emissions are slowing down, despite current warming rates being at an all-time high. This highlights the need for nimble policy-making, responsive to the latest evidence about the state of the climate system. “Time is no longer on our side. Access to up-to-date information is vitally important,” he warns.
The scientists’ revelations in the journal Earth System Science Data also show how key indicators have evolved since the publication of the IPCC’s Sixth Assessment Working Group 1 report in 2021.
Recent data reveals that human-induced warming, predominantly due to fossil fuel burning, averaged at 1.14°C for the last decade (2013-2022) above pre-industrial levels. This is a rise from 1.07°C between 2010 and 2019. Now, the pace of increase is over 0.2°C per decade.
Additionally, greenhouse gas emissions have reached an all-time high, with human activities releasing approximately 54 (+/-5.3) billion metric tons of carbon dioxide into the atmosphere annually over the last decade (2012-2021).
While there has been a move away from coal burning, it has ironically added to global warming by reducing particulate pollution in the air, which usually has a cooling effect.
Professor Maisa Rojas Corradi, Chile’s Minister of the Environment, an IPCC author and scientist involved in this study, emphasizes the importance of regularly updating global change indicators. She says this is critical for maintaining urgency in addressing the climate crisis, allowing for informed decision-making, and fine-tuning national policies.
A critical insight from the analysis is the rapid decline in the remaining carbon budget, which is the estimate of carbon that can be released into the atmosphere to maintain a 50% chance of keeping the global temperature rise within 1.5°C.
As of 2020, the IPCC calculated the remaining carbon budget to be around 500 gigatonnes of carbon dioxide. By early 2023, this figure had halved to about 250 gigatonnes of carbon dioxide. This precipitous drop is due to the persistent greenhouse gas emissions since 2020, compounded by updated estimates of human-induced warming.
Professor Forster warns, “Even though we are not yet at 1.5°C warming, the carbon budget will likely be exhausted in only a few years as we have a triple whammy of heating from very high CO2 emissions, heating from increases in other GHG emissions and heating from reductions in pollution.”
If we aim to keep the 1.5°C goal within our reach and not just a fleeting image in our rearview mirror, we must work relentlessly and urgently to bring down emissions. The Indicators of Global Climate Change project aims to aid this endeavor by ensuring key players have timely and up-to-date data at their disposal.
Dr Valérie Masson-Delmotte, from the Université Paris Saclay, who co-chaired Working Group 1 of the IPCC’s Sixth Assessment report and was involved in the climate indicators project, shared a similar sentiment.
She said, “This robust update shows intensifying heating of our climate driven by human activities. It is a timely wake up call for the 2023 global stocktake of the Paris Agreement – the pace and scale of climate action is not sufficient to limit the escalation of climate-related risks.”
It’s important to remember that every incremental increase in global warming intensifies climate extremes. This includes heightened frequency and intensity of hot extremes, heavy rainfall, and agricultural droughts.
The Indicators of Global Climate Change (https://igcc.earth/) aims to keep this information on greenhouse gas emissions and climate change accessible and up-to-date. The platform will provide annual updates on greenhouse gas emissions, human-induced global warming, and the remaining carbon budget.
Inspired by the financial industry’s approach to information presentation, software developers expanded on a successful climate dashboard, the Climate Change Tracker, to build the IGCC website. This interface allows the public to digest complex climate data in a user-friendly format, further enabling informed climate action worldwide.
A tipping point in the context of climate change refers to a threshold or a point of no return in the climate system. When this point is crossed, drastic and potentially irreversible changes occur.
This phenomenon is a product of positive feedback loops in the climate system, where a change in one aspect, like greenhouse gas emissions, can amplify other aspects, leading to accelerated warming or climatic shifts.
Several key tipping points have been identified by scientists. Here are some of them:
The polar ice sheets in Greenland and Antarctica have a considerable effect on the global climate. Once these ice sheets start to melt, a feedback loop can begin where melting ice reduces the Earth’s albedo (reflectivity), which means more sunlight is absorbed, leading to more warming and thus more ice melting. If all of the Greenland ice sheet were to melt, it could lead to a global sea-level rise of about 7 meters.
Large areas of the Arctic are covered in permafrost – ground that remains frozen throughout the year. This permafrost contains vast amounts of carbon. As the world warms, this permafrost thaws, releasing this carbon as greenhouse gases (carbon dioxide and methane), which in turn accelerates global warming.
The Amazon rainforest, often referred to as the “lungs of the Earth”, is another potential tipping point. Deforestation and rising temperatures could cause a significant portion of the forest to die back and transition into savannah, releasing massive amounts of CO2 stored in the forest biomass and reducing the amount of CO2 that the forest can absorb.
The Atlantic Meridional Overturning Circulation (AMOC), a major ocean current system, plays a key role in regulating the global climate. Increased freshwater from melting ice can disrupt this system, leading to potentially severe consequences for weather patterns, particularly in Europe and North America.
Crossing any of these tipping points could lead to severe and rapid changes in the global climate system. Many scientists believe that we are already close to or have crossed some of these tipping points, but there is ongoing debate over precisely when and how these thresholds will be breached.
Understanding and predicting these points is a major focus of climate research and adds urgency to the need for significant reductions in greenhouse gas emissions.