The climate change debates have been characterised by diverse opinions at every level of society, especially the media.
The starting point for analysis of climate change is temperature, as everything else, like the amount of rain or rising sea levels, occurs because of the changes in temperature
There is convincing data on global temperature increases from multiple sources, such as NASA and the World Meteorological Organisation (WMO). In summary, 2024 was the warmest year in modern history at 1.6°C above pre-industrial levels and the ten years to 2024 were the hottest decade.
The State of the Global Climate 2024 Report included a graph of temperature change for the period 1850 to 2024. That graph shows a scary geometric progression in temperature change, with the scariest part being most of the temperature increase has occurred in the last 50 years.
The temperature increases have led to other events like sea level rises, due to the expansion in the volume of sea water as it heats up, and the melting of ice, mainly sea ice. The sea level increased by an average of 1.4mm per year in the 100 years to 2000, though, more worryingly, the rate of change has been 3.4mm per year since the start of satellite recording in 1993.
The science
Nearly 100 per cent of climate scientists agree higher greenhouse gases, predominantly CO2, are the cause of the global temperature increases.
There are multiple measures of CO2 levels over time. The worrying issue is the much higher rates of change in recent times. CO2 levels were rising by about 5ppm (parts per million) per decade from 1900 until the 1970’s when the subsequent CO2 increases had increased to approximately 20ppm per decade.
There is scientific proof that the rise in CO2 levels is due to the burning of fossil fuels. Carbon isotopes C12, and C13 which has an extra neutron, are emitted in natural events like volcanoes and bushfires, and in burning fossil fuels, but burning fossil fuels produces much more C12 than C13. The ratio of C13 to C12 has declined at a more rapid rate since 1970. Core ice samples show the change in the ratio is four times larger today than the natural variability observed over hundreds of thousands of years.
The credibility of any options to manage the amount of fossil fuel that is burnt depends on the seriousness of the problems created by the higher CO2 levels, and the evidence here is far less convincing. This lack of evidence is the biggest barrier to concerted action, both in Australia and internationally.
There are environmental, social, and economic impacts that could be analysed. There are recognised techniques for doing this type of analysis but it is much harder for any government to convince the community to take these forward-looking, assumption-based calculations seriously, than if there are actual measures of what has already occurred in the past years, like rises in temperature and sea levels.
Community concern is also weakened by comments like the latest event was ‘worst since 1970’, which suggests that the latest event may have been naturally occurring rather than a climate change-caused event.
From this layman’s perspective, before more of the community will accept the need to pay for extra policies to reduce global emissions, the environment, social and especially economic impact of climate change requires additional analysis and proof, then articulation in a form most of the community understands.
Developing economies
Getting the policy mix right won’t be easy. The world target of net zero emissions by 2050 is unlikely to be achieved with current technology as there are so many highly populated nations with low emissions because they have underdeveloped economies. For example, India is relatively underdeveloped, has the largest population in the world at 1.4 billion and has amongst the world’s lowest CO2 emissions per capita. The same applies to Indonesia and Brazil, each with populations of over 200 million.
China, classified as a developing economy, is the world’s largest CO2 emitter by a large margin but only accounts for 30 per cent of the world’s emissions. 60 per cent of the world’s population are in countries that each have less than two per cent of the world’s emissions and many of these countries have underdeveloped economies.
In all of these countries CO2 emissions are certain to increase significantly in the next 25 years as their economies become more developed.
Australia has amongst the highest emissions per capita in the world for various reasons, including because we are a developed economy.
The relatively small population means Australia only accounts for about one per cent of global emissions and whatever Australia does will have little impact on global emissions. Some commentators argue that because of that minimal impact on global emissions, Australia should not take climate change action that harms the Australian economy.
Taking responsibility
As Australia is one of the richest countries in the world in absolute terms let alone per capita terms, most Australians would agree that Australia should at least do its share to limit CO2 emissions. Both major political parties support action to reach the net zero emissions target by 2050. Most focus is on electricity generation which accounts for about 30 per cent of CO2 emissions and is the largest single contributor to emissions in Australia and globally.
Australia’s efforts to reduce CO2 emissions could include research to enhance techniques all countries can use to limit CO2 emissions, as Australia has the financial and research capacity to do this type of work. Australian research is likely to have a far greater impact on global emissions than spending money to reduce emissions in Australia.
It is hard to know where this will all end up. In the short term, it isn’t looking very promising internationally, particularly as the Trump administration is certain to disregard climate change concerns and that will prompt others to follow suit while he is in office. Within Australia, we have just had an election with renewable versus nuclear generated electricity the focal point on climate change matters. Labor’s win means renewables will be the main policy push in electricity, though I also suspect the climate change agenda will be somewhat broader than renewables, at least for the next three years. Let’s hope so.
♦ Ken Clarke worked as a researcher and policy analyst in Canberra, Port Moresby, London and Darwin, mostly in the public sector. This included advising the NT Government as Under Treasurer on social, fiscal, and economic issues.
For four decades The Echo has printed the stories some people loved, some people hated, and some pretended not to read. If you want us to keep telling the truth, the real truth, not the sugar-coated version. We’ll need your support to keep the presses rolling. 
