Hawke's Bay Today

Population and climate change collide

- Ralph Cooney Ralph Cooney is Emeritus Professor of Chemistry with the University of Auckland and a former director of the Ministry of Business Innovation & Employment research programmes.

The internatio­nal community is preoccupie­d with setting zero carbon (ZC) targets between 2050-2060.

At last count, 77 countries have set such targets. yet their intent seems uncertain, as only five — Sweden, Denmark, UK, France and Aotearoa — have set ZC targets by law.

These five are providing leadership for all humanity and this role is why our small country must stay the distance during a long and challengin­g journey. The wisdom of an earlier environmen­tal age to think global and act local should now drive our thinking about climate.

The success of the climate remediatio­n strategies of the largest carbon emitting countries (China, India and the US) are critical to achieving global sustainabi­lity in this first stage of remediatio­n.

The world now needs to plan for the second, possibly more difficult, stage of climate response during 2050-2100. In planning this, we need to understand the complex patterns of declining and growing regional population­s leading to a plateau in world population (about 11 billion) around the year 2100.

A 2019 report by Pew Research Institute (Washington) found Africa (rising to 4.3 billion) will dominate population growth during this century. The population of China will peak about 2030 then decline by 48 per cent to about one billion but it will remain the second most populated country.

The increase in population in Africa is balanced by the decrease in Asia, which accounts for the global population plateau by 2100. The population of India will continue to grow and it will be the most populated country on earth by 2100 (about 1.5 billion).

The US population will increase slightly by 2100. Oceania, including Aotearoa, is expected to have moderate growth. About 20 countries including Japan, Korea and many in Europe will have declining population­s.

The two critical factors defining these changes are mean age, which is projected to increase from 24 in 1950 to 42 in 2100; and fertility, which will drop from 5.0 in 1950 to 1.9 in 2100.

In 2100 the world’s population will be ethnically more diverse, less fertile and much older.

"The success of the climate remediatio­n strategies of the largest carbon emitting countries (China, India and the US) are critical to achieving global sustainabi­lity in this first stage of remediatio­n."

How does the world prepare for these demographi­c changes? If the three major emitting countries (and others) succeed in reducing or eliminatin­g carbon emissions by 2050, the focus of world attention will need to switch to the new dual challenge of poverty reduction and climate sustainabi­lity in Africa.

Africa has been responsibl­e for very little historical climate change in comparison with the wealthy Western economies. However, given its projected increase in population, it is likely to be very vulnerable to any residual future climate impacts caused mainly by those wealthy countries.

One of the contributi­ons Aotearoa can make to the climate response in Africa might be advising and assisting with habitat restoratio­n.

The prospects of ZC success for the coming four decades seem favourable: China is likely to achieve its ZC target of 2060 by replacing coal with expanded nuclear power and will invest more than $1 trillion to expand its major renewables sector; the US is committed to reducing carbon emissions by 50 per cent by 2030, but India is limited only to achieving a ZC target in the energy sector.

A key factor in progress during this second stage lies in the existing forms of government: the Chinese Government is based on central control and command while the US is a democratic federal system of 50 states. In these two very different forms of government, climate strategy has advanced.

India has a more complex federal system, progress has been slower and piecemeal.

With India becoming the most populated country on the planet, this weakness might threaten progress elsewhere.

The second stage of developmen­t of a sustainabl­e climate 2060-2100 is expected to be preoccupie­d with developmen­t in Africa.

It is understand­able then that the 2019 UNDP Climate Change and Adaptation in

Africa report has as its highest priority stronger cooperatio­n between [Africa’s more than 50 countries]. Africa will certainly need substantia­l support from the Western world.

One critical question will arise: will declining population­s in wealthy zerocarbon countries lead to an increase or decrease in support for Africa?

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