In recent weeks, the world has seen unexpected flooding in Europe and China, record-breaking heat waves in the United States, and deadly wildfires in Siberia, Turkey and Greece. Amid grim predictions of a continuing increase in the frequency and intensity of these extreme weather events, all attributable to global warming, scientists are expected to present the most comprehensive health check of Earth’s climate on Monday.
Geneva-based Intergovernmental Panel on Climate Change (IPCC) to release Part I of its Sixth Assessment Report, the periodic status verification that has now become the most widely accepted scientific view the state of the Earth’s climate. This part of the report will present the latest scientific knowledge on the climate system, how and why it is changing, and the impact of human activities on this process.
The second and third parts of the report, dealing with the expected impacts of climate change and the actions required to prevent the worst impacts, are due out next year.
The previous five assessment reports (see box) published since the inception of the IPCC in 1988 have formed the basis of international negotiations on climate change, and the actions that governments around the world have taken over the past three decades to limit rising global temperatures. Their value has been recognized worldwide and the Fourth Assessment Report, released in 2007, won the IPCC the Nobel Peace Prize.
Each of these voluminous reports, the last two spanning thousands of pages, build on the previous ones with up-to-date knowledge and understanding of the climate system. All, from the first in 1990, have been adamant that the increase in global surface temperatures since the 1950s was most likely caused by human activities, and that any increase beyond 2 ° C, relative to at the temperatures of the late 19th century, would make Earth an extremely difficult place for humans and thousands of other species of plants and animals to live.
The reports also presented projections for the temperature rise through 2100 under different scenarios and the type of impacts that can be expected in each of these pathways.
In addition to incorporating the latest scientific evidence available, the Sixth Assessment Report also attempts to provide more actionable information to help governments make policy decisions.
REGIONAL FOCUS: So far, the IPCC assessment reports have presented global scenarios. However, it is likely that there are large variations in the expected impacts of climate change from region to region, as recognized by the assessment reports themselves. The sixth assessment report will put much more emphasis on the regional assessment. Thus, it is expected that this report will likely indicate what the sea level rise scenarios are in the Bay of Bengal region, and not just what the average sea level rise in the world is. is likely to be.
EXTREME EVENTS: The focus is expected to be more on extreme weather events, like the ones we’ve seen in recent weeks. Linking individual extreme events to climate change has always been questionable. But in recent years, there have been significant advances in the science of attribution, allowing scientists to tell if a particular event was the result of climate change. The science of attribution will likely figure prominently in the report.
CITIES: Densely populated mega-cities are said to be among the most vulnerable to the impacts of climate change. The sixth assessment report is expected to present specific scenarios on the impacts of climate change on cities and large urban populations, as well as the implications for key infrastructure. This should only be included in the second part of the sixth evaluation report due next year.
SYNERGIES: The IPCC should present a more integrated understanding of the situation, cross-link the evidence and discuss trade-offs between different options or pathways, and also possibly cover the social implications of countries’ action on climate change.
Why is this important
The IPCC assessment reports have been extremely influential in guiding dialogue and action on climate change. The first assessment report led to the establishment of the United Nations Framework Convention on Climate Change, the framework agreement under which international negotiations on climate change take place every year. The second assessment report served as the basis for the 1997 Kyoto Protocol which lasted until last year, and the fifth assessment report, which came out in 2014, guided the Paris Agreement.
The global climate architecture is now governed by the Paris Agreement, which replaced the Kyoto Protocol from this year. There has been enough evidence to suggest that global action was well below what was needed to keep temperatures below 2 ° C, as required by the Paris Agreement. In the immediate term, the IPCC report could serve as the most important warning to the rapidly closing window of opportunity to stop rising temperatures to unacceptable levels and push governments to take more urgent action.