Act together, act now on climate change and global warming

There is little doubt that 2023 is a year of extreme weather. Throughout the last eight months, there has been an avalanche of shocking photos and videos of climate-related disasters on social media: wildfires in Chile, North America and southern Europe, unbearable heatwaves across Asia, and deadly cyclones hitting south-eastern Africa. The threat of climate change is more pressing than ever. In face of one of the biggest challenges of the 21st century, there is an urgent need for humankind to rethink its coping strategies and priorities.

FLASS FORWARD is glad to have Dr Norman Cheung from the Department of Social Sciences and Policy Studies to share with us his thoughts on the alarming issues of climate change, including the worst consequences anticipated if we do not heighten our response to it and what people should do to contain the crisis. A trained climatologist, Dr Cheung has been following issues of climate change for many years in the UK and Hong Kong. When he was working in the UK, he was regularly invited by various media organisations, including SKY NEWS, Bloomberg, Channel 4, Channel 5, LBC, Green TV, Al Jazeera, STINFO and Financial Times, to give commentaries on extreme weather, hurricanes, natural hazards and disaster management.

After obtaining his DPhil in tropical climatology from the University of Oxford, Dr Cheung worked as a lecturer and then Senior Lecturer in Environmental Hazards and Disaster Management at Kingston University London. Upon returning to Hong Kong, he joined the SCOR Reinsurance (Asia) Company Limited, one of the world’s top five reinsurance companies, as a Senior Catastrophe Analyst. He taught at the Hong Kong University of Science and Technology before joining EdUHK in 2017-2018. Besides conducting research, Dr Cheung is zealous about educating the next generation to be climate-sensitive.

 

Dr Norman Cheung Kin-wai

Various climates have been recorded throughout history. Earth has experienced five ice ages (glacials) with warm periods (interglacials) in between on roughly 100,000-year cycles for at least the last 1 million years. Climate change means that temperature is constantly increasing.

It needs to be emphasised that the global average temperature has only risen by about 1°C for the last 100 years, but it continues to rise (Fig 1). At the present rate, the global temperature rise will reach 1.5°C above pre-industrial levels around 2040 (IPCC, 2018). Two things of note: first, the temperature has been increasing rapidly in recent decades. Secondly, this 1.5°C is so critical because of global warming; it increases the water holding capacity of the atmosphere (by about 7% per 1°C warming, Trenberth, 2011), thus creating greater evaporation over land and sea surfaces that has huge knock-on effects on the feedback loops of the atmospheric and oceanic systems that interact with each other.

Technically speaking, the range of temperature fluctuations recorded within the threshold is deemed normal. However, the frequency of extremely and abnormally warm years has been increasing greatly since the start of industrial revolution.

We have been seeing some of the warmest years ever recorded – 2015, 2016, 2017, 2019, 2020 and 2022 – within the last 10 years (WMO, 2022), as well as extreme heatwaves in the Southwest of the US and Mexico, Southern Europe, and China in 2023. Temperatures reached 52°C on 16 July in Death Valley in the US, as well as in northwest China (CNN, 2023). July 2023 even set a record of the highest monthly sea surface temperature anomaly (+0.99°C) of any month in NOAA’s 174-year record (NOAA, 2023).

Some people argue that climate change is a natural phenomenon, rather than something caused by human activities. Indisputably, climate change can be caused by natural forcings such as Milankovitch cycles (changes in the orbit of the Earth), El Niño and Southern Oscillation (ENSO), solar irradiance, volcanic eruptions, and shifts in the Earth’s crust (known as plate tectonics). However, Milankovitch cycles take place over tens or hundreds of thousands of years. Any increase in solar energy would make the entire atmosphere of Earth warm, but we only see warming in the bottom layer. Volcanoes can warm the earth but they are not frequent enough to explain the warming today. Tectonic movement is in a scale of a million years.

Then, can we blame the record-breaking temperatures of 2023 on the current El Niño phenomenon? El Niño is the unusual warming of the sea surface temperature in the Central Pacific Ocean due to the slackening trade wind from the Eastern Pacific Ocean. Stronger rising air from the warm sea surface water in the central Pacific Ocean changes the latitudinal circulation of the atmosphere in the Pacific. This can explain the occurrence of heat waves in Southeast Asia.

However, the heat waves over Europe are less likely due to the impacts of El Niño. There was an absence of the usual wetter southwest US and Mexico generated by the extended Pacific Jet stream moving south of its neutral position under El Niño. What happened was the dominance of heatwaves from the northwest to southeast of the US, with extreme temperatures recorded in the four corner states, Texas, and Florida. The full swing effects of El Niño 2023 are yet to be seen, as it is expected to continuously strengthen around Christmas 2023, and there is a lag in bringing about its impacts. Because of that, we will have massive heatwaves in different parts of the world in 2024.

The extreme high temperatures of 2023 are a result of global warming. Human activities, principally through emissions of greenhouse gases, have unequivocally caused global warming (IPCC, 2023). Large scale deforestation in the Amazon basin, southeast Asia, and Congo tropical rainforest for last few decades have led to serious soil degradation, the development of gullies and badlands, and desertification. Over-irrigation on arable farming in Africa has led to salinisation and soil degradation, further worsening the desertification process. A combination of an excessively long dry period without rain, bare ground surfaces without vegetation, and high albedo exacerbates the spatial and temporal scale of drought we have noticed dominating the climate in Sahel and northwest China.

Under rapid population growth and large-scale urbanisation and industrialisation after World War II, we have been seeing the birth of megacities such as Tokyo, Mumbai, Shanghai, and so on. Through the change from agriculture to urban land use, massive construction and cemented areas, air pollutants such as sulfuric acid, nitric acid, methane, and carbon dioxide coming from homes and industries are trapped under the heat island effect and act as GHGs (greenhouse gases) that aggravate the greenhouse effect. The melting of glaciers and sea-ice in the polar region due to the warming process has led to a rise in the global sea level. Destructive coastal floods are sinking low-lying small island states and causing the emergence of climatic refugees.

The link between climate change and various atmospheric, hydrological, and biological hazards is undeniable. A warmer atmosphere will provide more energy for the formation of hurricanes and tropical storms, which would wreak havoc to coastal areas along their path. Research confirms that the frequency of tropical storms may be declining (Chand et al., 2022) but the intensity of hurricanes is increasing (Knutson et al., 2021), such as super typhoons Hato (2017) and Mangkhut (2018). A warmer atmosphere provides massive potential energy and moisture for the formation of heavy thunderstorms which result in extreme flooding. On the other hand, global warming causes extreme heat waves, drought, and forest fires (Fig. 2).

Evidently, climate change brings disasters to human beings, but most people are still being sluggish with – if they are not outright ignoring – taking action to slow down the warming of Earth. Most people would rather respond to imminent hazards, such as approaching typhoons or floods which pose tangible threats to them, than deal with their far-reaching causes.

We should know that climate change is a process of which rising air temperature and intensifying rainstorms cause dramatic impacts. Our complacency costs us too much to bear in terms of loss of lives and property. To reduce vulnerability and increase our resilience against hazards of unprecedented scale of power and damages, we should develop comprehensive hazards and disaster management plans for our communities. Bear in mind, we have not seen the worst consequences of climate change yet. The magnitude of the destructive power of these hazards would be greater on a warmer Earth.

The carbon dioxide released from burning fossil fuels is the main driver behind global warming. Fig. 3 shows more than 60% of total global energy consumption is still from the burning of fossil fuels (Energy Institute Statistical Review of World Energy, 2023), although most countries have been undertaking massive projects to harness renewable energies such as solar (China), wind (US), hydroelectric power (China), and tidal wave energies (UK).

Let us face it: it is impossible to terminate the burning of fossil fuels entirely under the current situation. Therefore, there is increasing emphasis on energy efficiency and conservation activities. That means delivering more services for the same energy input and delivering the same number of services for less energy input, with the goal of reducing energy losses at any stage of the life cycle (extraction, conversion, transport, transmission, and use).

Another method is carbon sequestration, which means putting carbon dioxide into long-term storage. There are two types of CO2 sequestration methods: a) terrestrial sequestration which uses land management practices (wetlands, restoration, afforestation) to enhance removal of CO2 from the atmosphere; and b) geologic sequestration/Carbon Capture and Storage (CCS) which involves capturing CO2 before it enters the atmosphere (generally at the site of a power plant or major emitter) and injecting it deep underground or storing in the oceans. But we are not sure about the potential health issues with the CO2 being injected deep into the oceans.

To keep global warming to no more than 1.5°C, emissions need to be reduced by 45% by 2030 and reach net zero by 2050. More countries are committing to net-zero emissions by 2050 (UNEP, 2022). More than 130 countries globally have proposed their own carbon neutrality goals by 2050 or 2060 (Zhao, 2022).

Starting from the Intergovernmental Panel on Climate Change (IPCC) that conducted research on climate change in 1988, through to the United Nations Framework Convention on Climate Change (UNFCCC) 1992, many countries agreed with the direction of cutting GHG emissions, with the Kyoto Protocol 1997 setting the limits of GHG emissions for Most Developed Countries (MDCs), the Copenhagen Accord 2009 saying that China, US and other major Least Developed Countries (LDCs) agreed to cut GHG emission. The Durban Platform 2011 agreed to establish a legally binding agreement on emission cuts for both MDCs and LDCs that would be effective in 2020, and in the Paris Agreement 2015,  all countries agreed to keep the increase in global temperature below 2°C, which was later revised to 1.5°C.

Since 1995, the United Nations Climate Change Conferences of the Parties (COP) have met every year to review the national communications and emission inventories submitted by the Parties to assess the effects of the measures taken by the Parties and the progress made in achieving the ultimate objective of the Convention.

However, international conflicts of interest and different paces of economic development make it difficult for all parties to come to a consensus on how to reduce the use of fossil fuels. Without the full commitment of international cooperation, the agreed-upon goals will never be achieved. As a matter of fact, we are far from being on track when it comes to carbon-neutral or carbon-zero goals. The Glasgow Climate Pact called on all countries to revisit and strengthen the 2030 targets in their Nationally Determined Contributions (NDCs) by the end of 2022, but only 24 new or updated climate plans were submitted by September 2022 (UN, 2023).

It is pointless arguing whether the extreme high temperatures are just within our climatic oscillation or climatic variability. Nor shall we hold any hope for the climate skeptics who have doubts about the existence of global warming intrinsically. Instead, we need to take action now. Without action, the tipping point that can trigger huge climatic disasters will likely be reached in the 2030s once the 1.5°C temperature rise above pre-industrial levels (IPCC, 2023) occurs. IPCC warned us that there could be a 4.1°-4.8°C temperature rise by 2100 in the business-as-usual scenario of their climate change model.

Even if we shut down the release of carbon dioxide now, carbon dioxide will stay in the atmosphere for between 300 and 1000 years (Buis, 2019), continuously intensifying the greenhouse effect. By keeping our temperature rise below 1.5°C above pre-industrial levels, the high temperature rises will gradually peter out.

We must act together, and act now. Through environmental, social and governance (ESG) and environmental, social and climate change (ESCC) risk assessment, governments, business leaders and the general public should be made aware of the causality between climate change, climate hazards and environmental sustainability, which will hopefully change the attitudes and behaviours of people to take more significant and immediate action on climate mitigation and adaptation. However, if the intense geopolitics and economic protectionism prevail and slow the transition from fossil fuel burning to carbon-neutral and net-zero operations, we will probably continue to record ever hotter temperatures in the coming years.

References:

Buis, A. 2019. The Atmosphere: Getting a Handle on Carbon Dioxide. NASA: Global Climate Change (Accessed 31st Aug 2023)

Chand, S.S., Walsh, K.J.E., Camargo, S.J., Kossin, J.P., Tory, K.J., Wehner, M.F., Chan, J.C.L., Klotzbach, P.J., Dowdy, A.J., Bell, S.S., Ramsay, H.A. and Murakami, H. 2022. Declining tropical cyclone frequency under global warming, Nature Climate Change, Vol. 12, July 2022, 655-661.

CNN 2023. ‘This is just the beginning’: Extreme heat around the world as fires rage in southern Europe. July 18, 2023. (Accessed on 2nd Sept, 2023)

Energy Institute Statistical Review of World Energy, 2023, (Accessed on 3rd Sept, 2023)

IPCC 2018. Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty, FAQ Chapter-1, doi: (Accessed on 2nd Sept, 2023)

IPCC 2023. Summary for Policymakers. In: Climate Change 2023: Synthesis Report. Contribution of Working Groups I, II and III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, H. Lee and J. Romero (eds)]. IPCC, Geneva, Switzerland, pp 1-34, doi: https://www.ipcc.ch/report/ar6/syr/

Knutson, T.R., Chung, M.V., Vecchi, G., Sun, J.G., Hsieh, T.L. and Smith, A.J.P. 2021. Science Brief Review: Climate change is probably increasing the intensity of tropical cyclones. In: Critical Issues in Climate Change Science, edited by: Corinne Le Quere, Peter Liss & Piers Forster.

NOAA National Centers for Environmental Information, Monthly Global Climate Report for July 2023, published online August 2023. (Accessed on 2nd Sept, 2023)

Trenberth, K.E. 2011. Changes in precipitation with climate change. Climate Research, Vol.47: 123-138. Doi: 10.3354/cr00953

UN 2023. For a livable climate: Net-zero commitments must be backed by credible action. (Accessed on 4th Sept, 2003)

UNEP 2022. UNEP Emissions Gap Report. https://www.unep.org/resources/emissions-gap-report-2022 (Accessed on 2nd Sept, 2023).

WMO 2022. Eight warmest years on record witness upsurge in climate change impacts. Press Release Number: 06112022 (Accessed on 2nd Sept, 2023)

Zhao, W.J. 2022. China’s goal of achieving carbon neutrality before 2060: experts explain how. National Science Review, Vol. 9, Issue 8, August 2022, nwac115, (Accessed on 2nd Sept, 2023).