Figure 1: This graph shows how CO2 levels have varied in the past thousands of years compared to today. The data before 1950 shows how CO2 emissions should vary in a world without human intervention. The graph after 1950 shows how CO2 has far exceeded a level that has never been crossed in the past 800,000 years. The impacts of human actions are far more significant than the forces of nature. (picture taken from climate.nasa.gov (4))

It is this long-term time scale outlasting several lifetimes, that makes climate change an especially counter-intuitive problem. Anecdotal evidence usually captures such a minute picture of the overall problem that it is not representative, nor is it a credible base for scepticism. Going back to the questions posed earlier in the article: isn’t CO2 safe? Isn’t it getting colder? Put into perspective, we realise that: CO2 is safe in small doses, but not at the level we are emitting (see figure 1), and though it does feel like it is colder in the short run, the graph quickly bounces back and trends upwards in the long run. 

Climate Projections and How to Use Them

Understanding this, Scientists have long tried to project scenarios in the future to warn the world of the dangers we face. They create sophisticated models and computer programs that simulate how the climate would change if our level of emissions changed (5). However, people misunderstand how to use these projections. Common criticisms are: ‘five years ago, you mentioned that we must hit 2.0˚C, now you say 1.5˚C what should it be?’ or ‘in the previous report, you said that we are on track to 3.0˚C, now you say that it is 2.9˚C – isn’t this just a manipulation of results to suit the narrative?’

Firstly, projections are not predictions. Projections are plausible scenarios that might happen if we choose to take a certain set of actions. For example, suppose we had a strong commitment from major countries to limit their emissions, and if green technologies continue to improve, then we may be on track to a 1.5˚C temperature rise by the end of the century. On the other hand, if we continue a business-as-usual scenario where no further action is taken, then we may be on track for a 3.0˚C temperature rise instead (2,6). If you are a fan of Marvel, you may be familiar with the concept of the multiverse; this is similar. Every possible decision creates a branch of an alternate universe that could be true; it is up to us, then, to decide. 

Addressing the first question now: ‘five years ago, you mentioned that we must hit 2.0˚C, now you say 1.5˚C, what should it be?’ The nuance to this question is that science does not tell us what is ‘the right thing to do’ it can only present all the possible choices ahead for us and their associated risks (see Table 1). Science shows us that the higher our surface temperatures are, the more risks we are exposed to. Choosing our acceptable risk level remains debatable, which is resolved through forums such as the UN Climate Change COPs. The change from 2.0˚C to 1.5 ˚C is not a scientific choice but through political pressure from nation-states most affected by the crisis, and a very legitimate one at that (7). At 2.0 ˚C, some countries (i.e. Antigua, Barbuda, Maldives, Fiji, Kenya, Mozambique, Samoa, and Barbados) will not survive (8). The point here is that the acceptable level of risk has always been a political choice, and since COP25 in Paris, we have chosen for it to be 1.5˚C. The scientific conclusions have never changed; it is detrimental to discredit all other areas of climate science for this reason. 

Table 1: Science does not ‘decide’ what is the best option. It merely presents all possible pathways and risks. Policymakers balance feasibility and the acceptable level of risk. This table is an oversimplified version of the pathways and potential impacts being presented. (2)

The second question is more of a misunderstanding of how projections work at all. First, all projections come with a level of uncertainty. So, when a report says that we are on track to 3.0˚C, it means that at the current rate, we are going to hit temperatures around 3.0 C (i.e. 2.9˚C – 3.1˚C depending on how accurate the model is built to be), with the best guess being at 3.0 ˚C. So if projections change from report to report, it means that an improved model has been used with an improved best guess. It doesn’t change the conclusion that hitting these temperatures is a very high risk. Second, the likely reason why likely temperatures have dropped is that we have changed our course of action to adopt more environmental policies. Again, a projection is not a prediction. So, where previously we were on track to 3.0 ˚C, with the newer policies in place, we are now on track to 2.9 ˚C instead. A different branch within that hypothetical multiverse.

From a communications perspective, this is a tricky problem to have. In the best-case scenario, we would change our course of action and therefore prove our initial projections wrong (which is easily twisted to undermine the public’s trust in climate science). In the worst-case scenario where we don’t do anything, our projections are eventually proven right, in which case it would be too late. The media, then, must take more care when quoting these projections, ensuring the appropriate context is in place. Otherwise, it easily erodes trust among the public towards the validity of the science. 

For these reasons, the scientific community has often been portrayed as unsure – but this is not true. Scientists have been sure for many decades, even after multiple attempts to prove themselves wrong; it is more so that the nuances are not understood well by the public. We must remind ourselves that projections are not predictions. Merely a set of possible long-term futures based on our near-term decisions. With that in mind, we must use it wisely to guide our future actions. 

The Impacts of Climate Change

‘Keeping 1.5 ˚C within reach’ and ‘to reach net-zero by 2050’ are heuristics for much wider visions of the future: the increase of droughts, floods, the collapse of ice sheets, the drying up of drinkable water streams and eventually the inability to grow food at all. In general, as surface temperatures increase, the severity and frequency of each risk increase (2). On top of that, there are certain ‘tipping points’ (i.e. the collapse of ice-sheets, or the flip in ocean currents) that once passed, permanently alter the climate in the backdrop for the next decades to centuries (in a way that further amplifies all stated impacts) which are irreversible. At the moment, scientists estimate that about 15 tipping points are already active, with many more to ‘tip’ at around 1.5˚C and further at 2.0 ˚C (9).

One thing that people often get wrong when it comes to climate change, is that it is not that one day we will wake up and suddenly there is no water, or food or that everyone else is dead. Rather, these changes occur very gradually and unassumingly in the backdrop. What, then, does climate change look like? Perhaps today, it is easy to think of climate change as some faraway issue – news reports of a farmer in Africa or Latin America who can’t grow food this year – one might feel some sympathy (10). Perhaps in a few years, water gets scarcer and seems just a tad bit more expensive to buy – but that’s just something that is inconvenient at best (11). And then one day, many decades down the line, suddenly London, Tokyo and New York floods (12); or parts of the world become unhabitable as climate refugees seek new places to live (13); or we have lesser food sources than the required for all the people living in the world (14). The heatwaves feel longer and hotter – the killing of more and more each year (15). The number of people admitted to hospitals for cancer seems to increase slowly but surely (16). We realise then that it is too late to do anything, and there is nothing to do but to sit and wait for our own demise. 

It is this gradual and unassuming scale of impact that makes it so easy to be complacent. But the author reminds the reader that the impacts of climate change are very real indeed. In Malaysia, does it not seem like the temperature rises slowly but surely each year? And that the floods seem not only more frequent but almost expected? These are the impacts of climate change, slowly but surely. As a global community, we must act before it is too late.

References

• Climate System Dynamics and Modelling (Online Textbook) | Cambridge University Press
• Summary for Policymakers, Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the IPCC | IPCC
• Carbon Dioxide Exchange Between Atmosphere and Ocean and the Question of an Increase of Atmospheric CO2 during the Past Decades | Roger Revelle & Hans E. Suess
•  How do We Know Climate Change is Real? | NASA
• Earth Systems Models: An Overview | Gregory M. Flato
• Summary for Policymakers, Climate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the IPCC | IPCC
• Navigating the political: An analysis of political calibration of integrated assessment modelling in light of the 1.5 °C goal | Environmental Science & Policy Journal
• Mia Mottley, Prime Minister of Barbados at the Opening of the COP26 World Leaders Summit | UN Climate Change COP 26
• Exceeding 1.5°C global warming could trigger multiple climate tipping points | Science
• Kenya: Farmers Count Losses As Crops Wilt Due to Delayed Rains | Nation Team
• Water Scarcity | United Nations Water
• Consequences of twenty-first-century policy for multi-millennial climate and sea-level change | Nature Climate Change
• Climate Refugees | climaterefugees.org
• 4 Ways Climate Change Could Cause Food Shortages | World Economic Forum
• Heatwaves kill people – and Climate Change is Making it Much Worse | National Geographic
• The Climate of Health | Stanford News