Concern over climate change is on the rise, with effects of global warming dominating headlines of late.
In fact, warnings about climate change have been flagged for a few decades, as reported by the Intergovernmental Panel on Climate Change, or IPCC.
But what is the IPCC anyway, what have they been saying and why does it matter?
WHAT IS THE IPCC?
The IPCC is the leading international scientific authority on climate change. It is a United Nations body made up of 195 member governments, formed in 1988.
The IPCC works by convening thousands of scientific experts from around the world to summarise what is happening to the Earth’s climate system, highlight vulnerabilities to societies, and recommend both mitigation and adaptation measures.
It publishes comprehensive assessment reports every five to seven years, with the most recent Fifth Assessment Report (AR5) released in 2014.
The next report, AR6, is currently being drafted and will be published in 2021.
IPCC may also prepare special reports focusing on specific topics. For instance, a special report was released in 2018 to address how humanity can prevent global temperature rise of 1.5 degrees above pre-industrial level.
These reports are intended to provide governments with the knowledge needed to develop policies, without prescribing specific policy recommendations.
The reports have been key inputs in international climate change agreements and negotiations. AR5 served as a basis for the 2015 Paris Agreement, a landmark global accord that was adopted by nearly every nation to address climate change.
Many national science academies from around the world, including the Australian Academy of Sciences, the Chinese Academy of Sciences and the UK Royal Society, acknowledge the work of the IPCC to be the “consensus of the international scientific community on climate change science”.
WHO AUTHORS THESE SCIENTIFIC REPORTS?
Authors are nominated by governments or non-governmental organisations and selected based on their expertise as leading scientists.
The Panel tries to maintain geographical and gender balance during the selection of authors, and representation from both developing and developed economics.
Climate science is complex and requires careful observations and modelling of the Earth’s climate system.
The authors gather this knowledge from peer-reviewed scientific literature. They volunteer their time to prepare these reports, which take many hours to draft, revise and review.
Part of the challenge is in projecting future climate change, determining effective ways to address the challenges, assessing the uncertainty, and how to communicate all of this.
Each finding is accompanied with an expression of confidence (low or high), based on underlying evidence (limited or robust) and agreement among experts (low or high).
For example, authors are in high agreement that decarbonising electricity generation is a key measure to mitigate emissions.
However, the point that mitigation policies could hamper access to energy services for underserved populations is put forth with low confidence.
Each report undergoes a rigorous review process, with many experts helping to comment on the accuracy and completeness of the draft reports.
Given the iterative review process and number of reviewers involved, the IPCC’s technical reports are considered one of the most extensively reviewed scientific documents.
To give a sense of the scale of the task, the last AR5 report has more than 4,800 pages.
The preparation of the report involved 830 scientists from 80 countries. They assessed over 30,000 scientific papers. Additionally, 2,000 expert reviewers provided 140,000 comments, which were all addressed by the authors.
The drafting and reviewing process took years, to ensure that the content for policymakers is clear and accurately reflects the science.
The IPCC report preparation process is long but ensures an inclusive and transparent way of compiling credible, current knowledge on climate change, for benefit of governments, students and citizens around the world.
WHAT DO THE REPORTS SAY?
Past IPCC reports have concluded that human influence on climate change is clear, with “unequivocal and unprecedented” warming of our climate system.
Emissions of greenhouse gases that contribute to this warming are higher than ever.
We are on track to reach a temperature rise of 1.5 degrees Celsius at the current rate.
Every fraction of a degree of warming has grave consequences. If temperature change hits 2 degrees, our world will become startlingly different.
Impacts on people and ecosystems are likely to be irreversible, with risks to health, livelihoods, food security, water supply, human security and economic growth.
There will be almost no more coral reefs, more extreme weather events like superstorms, and many plants and animals will become extinct through habitat loss.
Sea level rise will drive populations away from small islands and low-lying coastal regions, and crop and marine fisheries yields will fall.
In order to limit these risks, greenhouse gas emissions must be substantially reduced. Limiting global warming will require rapid, far-reaching changes in all aspects of society.
Aside from mitigating emissions or limiting temperature rise, adaptation will be required as well.
In anticipation of the effects of climate change, governments and communities need to better develop resilience to potential disruptions.
The reports are an urgent call for action. The world’s scientists are reiterating that drastic action is needed for the continued survival of many species on this planet, including ours, within the short time frame of the coming decade.
WHY SHOULD SINGAPOREANS CARE?
While the IPCC reports do not focus specifically on individual nations, the likely climate-related effects that Singapore will experience have been portrayed by other studies – we can expect hotter days on our island, with more intense rainfall and dry spells incidents.
As a low-lying island state, Singapore is clearly vulnerable to sea level rise.
Singapore is also an open economy by necessity, and the challenges of addressing climate change in our immediate region matters greatly to us.
Significant deforestation is happening in Southeast Asia, to make room for urbanisation or agriculture. This land use change is a key contributor to emissions.
Many neighbouring cities are developing steadily, driving up demand for electricity. Much of this is generated by burning coal, the worst-polluting fossil fuel.
Southeast Asia is also identified to be most vulnerable to climate change, being more severely affected by rising seas and extreme weather events.
These have impacts on agriculture, fisheries and marine ecosystems, threatening regional water and food security as well as human health. The risk of poverty and likely mass migration is likely.
In order to reduce the emissions of heat-trapping greenhouse gases, bold steps need to be taken to transition rapidly to a low carbon economy. This means weaning ourselves eventually from the high dependency on fossil fuels, like coal and natural gas.
We will need structural changes to the way we currently use land, energy, urban infrastructure (including transport and buildings), and industrial systems to eventually reach “net zero” emissions of greenhouse gases.
A carbon-constrained world is a reality that all of us need to come to terms with. This reality has not emerged out of the blue, but it is one that many are still becoming aware of.
The IPCC reports provide scientific understanding and illuminate possible socio-technical pathways forward. With the knowledge, we can take decisive action to protect many in the coming future.
Lynette Cheah is an Associate Professor of Engineering Systems at the Singapore University of Technology and Design. She is currently serving as Review Editor for the chapter evaluating zero carbon options in the transport sector for the IPCC’s next Assessment Report.