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 countries have set ZC targets by law. These are Sweden, Denmark, UK, France and Aotearoa.
These five are providing leadership for all of humanity and this role defines why our small country must stay the distance during a long and challenging future 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 and possibly more difficult stage of climate response during the interval 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 and the population of China will peak about 2030 and then decline by 48 per cent to about one billion but will remain as the second most populated country.
The increase in population in Africa is balanced by the decrease in population in Asia, which accounts for the global population plateau by 2100. The population of India will continue to grow and it will be by far the most populated country on earth by 2100 (about 1.5 billion).
The US population will increase slightly by 2100 because of immigration. Oceania, including Aotearoa, is expected to have moderate growth.
About 20 countries including Japan, Korea and many in Europe will experience 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.
Those alive in 2100 will experience a very different world to 2021: the population will be ethnically more diverse, less fertile and much older.
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 then 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.
The United Nations Development Programme (UNDP) in 2019 published the Climate Change and Adaption in Africa report, which links poverty and climate change and an increased potential for eco-migrants and disease outbreaks and hence increased political instability.
One of the contributions that Aotearoa can make to the climate response in Africa might be advising and assisting with habitat restoration.
Returning to the global perspective, the increase in global population from 7.8 billion at present to 11 billion by 2100 combined with climate change is certain to degrade habitats further. The journal Global Citizen (2020) identified several ambitious ecological projects, which include The Great Green Wall, an African-led project that aims to create the largest living structure on the planet. This will span the Sahel region, which has become increasingly dry and barren.
This initiative aims to restore 100 million hectares of degraded land, sequester 250 million tons of carbon and create 10 million green jobs. It will provide fertile land, food security and strengthen the region's resilience to climate change.
Ethiopia and Nigeria have restored millions of hectares of land and Senegal has planted more than 10 million trees.
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 (no green-house gases) and will invest >$1 trillion to expand its existing major renewables sector; the US is now 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 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, which incorporates 50 states and which does not have a unifying central government.
It is understandable then that the 2019 UNDP report has as its highest priority stronger cooperation between these states. Africa will certainly need substantial support from the Western world, much of which has a declining population.
One critical question will arise: will declining populations in wealthy zero carbon countries lead to an increase or decrease in support for Africa?
• 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.