SINGAPORE: During the UN summit commemorating the fifth anniversary of the Paris Climate Agreement on Dec 12, Secretary-General Antonio Guterres urged national leaders to declare a “state of climate emergency”.
He lamented that G20 countries were channelling 50 per cent more of their COVID-19 stimulus to sectors related to fossil fuels, compared to those using low-carbon energy.
Indeed, some would argue G20 countries are advanced economies today because they have burnt fossil fuels and contributed most of the man-made carbon dioxide emissions causing climate change.
Most would argue the moral burden is on G20 countries to support adaptation and mitigation efforts across the world, especially in developing countries.
COUNTING BOTH METHANE AND CARBON DIOXIDE EMISSIONS
As a scientist who studies the Earth’s climate, my first instinct is to look for evidence that rich countries today account for most of the world’s historical carbon dioxide emissions.
From publicly accessible data at OurWorldinData.org, the seven leading economies that have emitted the most carbon dioxide from 1751 to 2017 (from before the start of the Industrial Revolution until now), are: The US (399 billion tonnes), European Union nations (353 billion tonnes), China (200 billion tonnes), Russia (101 billion tonnes), Japan (62 billion tonnes), India (48 billion tonnes), and Canada (32 billion tonnes).
These are also among the top eight economies by gross domestic product (GDP) in 2019.
However, carbon dioxide is not the only man-made greenhouse gas (GHG) that causes climate change. While it makes up 76 per cent, methane accounts for another 16 per cent of the annual global GHG emission of 49 gigatonnes of equivalent carbon dioxide in 2010, according to the fifth and most recent Assessment Report of the Inter-governmental Panel for Climate Change.
Although human society emits annually much less methane than carbon dioxide, methane absorbs about 30 times more radiant energy in a period of 100 years, which means one tonne of methane is roughly equivalent to 30 tonnes of carbon dioxide for its 100-year global warming potential.
How could climate change reshape your dinner? Listen to an expert break it down on The Climate Conversations podcast:
As about half of anthropogenic methane comes from agriculture today, and this fraction was even higher in pre-industrial times, even ancient agrarian societies must be held responsible for methane emissions.
But how far back the timeline should stretch is unclear. The Agricultural Revolution took place about 12,000 years ago, when mankind largely abandoned hunter-gatherer lifestyles and started planting crops and herding animals.
Modern nations began taking shape many millennia later. Even then, agricultural production data across societies were not collected or preserved for the most part in history.
DEVELOPING COUNTRIES’ EMISSIONS WILL ECLIPSE DEVELOPED COUNTRIES’
Current GHG emissions are just as important to climate change as past emissions.
The G20 nations include large, fast-developing economies which have seen some of the most rapid growth in recent years, like China, India, South Africa, Brazil, Saudi Arabia and Indonesia, which will continue to emit much GHG until 2100 and beyond.
For the remainder of this century, many Asian, South American and African countries outside the G20 are also projected to accelerate their industrialisation and agricultural production.
Some of their future economies would no doubt be big enough to challenge G20 members. Non-G20 nations together already make up about 27 per cent of the world’s GDP in 2019, larger than the leading G20 economy, the US, which accounts for about 16 per cent.
If they continue to exploit fossil fuels, especially natural gas which is cleaner than coal and oil, and perpetuate methane-producing farming practices, future history will only recount how one leading group of GHG-emitting nations was replaced by another group.
With proper planning, mitigation efforts today can be tailored to cost less than projected costs of adaptation to avoid the potential loss of life and property, and to replace damaged ecosystem services under future climate change scenarios.
Therefore, it is in the economic interest of non-G20 countries to finance in part their own shift towards renewable energies and sustainable agriculture today.
HARD TO PIN DOWN RESPONSIBILITY FOR USING FOSSIL FUELS
We often personify nations as though they are morally responsible for an action like an individual is. But the people comprising a nation at present are entirely different from those centuries ago.
To say that citizens of a nation today enjoy the fruits of past generations – and hence inherit the moral burden of their forebears – also ignores the fact that those fruits benefited people beyond that nation’s border, due to international trade.
For example, in the early 1800s, steam-powered cotton mills in England burnt coal for energy and produced textile that were exported and used all over the world.
Furthermore, in the 19th and most of the 20th century, fossil fuels were the only technologically feasible and commercially available large-scale energy source that could reliably power entire industries and raise living standards.
In this sense, the historical carbon dioxide emissions were an “unavoidable evil” in the pursuit of economic growth.
(Let’s also not forget the earliest scientific results providing evidence for the global warming effect of carbon dioxide was only published in 1896 by Swedish chemist Svante Arrhenius, long after fossil fuel adoption has become widespread across the world.)
Likewise, we should also expect poorer countries to continue using fossil fuels if they receive no technological or economic assistance today to access renewable energies.
G20 NATIONS ALREADY STEPPING UP CLIMATE COMMITMENTS
Attributing which economies should bear the cost of historical emissions seems an impossible task.
The good news is there is general consensus that G20 nations should bear more of the economic and technological burden for climate change, as with most challenges involving global commons, since they have the resources to do so. This is one of the longest standing social contract regarding climate action.
At the same time, non-G20 nations must act responsibly because they are now aware that GHG emissions cause the Earth to warm up. They should actively conserve forests, pursue renewable energies, and adopt sustainable agriculture with assistance from G20 nations.
The EU and China, the second and third largest cumulative emitters of carbon dioxide, have taken the lead in pledging ambitious climate actions at the recent 75th United Nations General Assembly.
The US, as the largest cumulative emitter, soon under a new presidency, is poised to make a comeback to the 2015 Paris Agreement.
From a pragmatic perspective, climate justice is best served if countries can get serious on collective climate action and invest in protecting the one world we live in, for the sake of us all.
Koh Tieh Yong is Associate Professor at the College of Lifelong and Experiential Learning, Singapore University of Social Sciences. In 2013, he served as an expert reviewer for the 5th Assessment Report of the Inter-governmental Panel for Climate Change.