The vast majority of scientists agree that humans are the direct cause of global warming. Time is running out. When are we going to take them seriously?
For many people today, the term ‘climate change’ is regarded as a mere inconvenience. Whether you’re looking for huge profits or simply struggling to make ends meet, there is no denying that “acting now” requires too much effort, especially due to the misconception that “nothing is certain about climate change” – dealing with the issue tomorrow sounds easier. The thinking of some is that “this hasn’t happened yet, so we can handle it when, and if, it actually happens”.
This could not be further from the truth. Climate change is happening right now!
Humanity has known about climate change since 1896, thanks to Swedish scientist Svante Arrhenius. He explained that a doubling of the atmospheric carbon dioxide (approximately 290 parts per million, or ppm, at the time) would result in a rise of 5 to 6°C of the average global temperature.
Measurements from Mauna Loa, Hawaii reveal that the concentration of atmospheric carbon dioxide has reached 411 ppm, a rise of about 42 per cent from the 1890s. Meanwhile, the average global temperature has risen from 13.7 to 14.9°C.
If we apply the numbers estimated by Arrhenius over 100 years ago, a 42 per cent rise of carbon dioxide should give us an increase of 1.05 to 1.26 °C. Although these are simple approximations, the changes measured coincide with this century-old estimate.
The Intergovernmental Panel for Climate Change (IPCC) Special Report of 2018 on ‘Global Warming of 1.5 °C’ further reinforces this and states that “human activities are estimated to have caused approximately 1°C of global warming above pre-industrial levels, with a likely range of 0.8 to 1.2°C”.
The term ‘global warming’ doesn’t mean that everyone around the world should be seeing temperature values at 1°C higher on their thermometers at home. What this actually means is that temperatures around the world are changing (some may rise, and others may fall), and when we average those numbers, we get a higher value than that of 100 years ago. This is a change in climate.
It is very important not to confuse weather and climate! An example of weather is the temperature you experienced in Valletta yesterday at midday, which is specific to that place and that moment in time. Climate is a collection of statistics that describes how one may expect the weather to change during a ‘normal’ year. That means that winter snows and storms will still happen.
So why should we care about a 1°C rise in average global temperature?
The rise of atmospheric carbon dioxide (and other greenhouse gasses) increases the energy stored in our atmosphere. This starts to destabilise the circulation patterns that redistribute the energy throughout the globe; the weather you experience is a consequence of these large-scale patterns, often shown during the weather report. These disrupt what one would consider normal weather until a new stable system is obtained.
This level of scientific understanding is not ‘guesswork’ but the result of thousands of studies
Think of it as ripples caused by throwing a pebble in a pond; the only issue is that we have been throwing trucks-full of pebbles, constantly, for over a hundred years, and the waves generated by this process are not stopping any time soon.
It’s important to note that this level of scientific understanding is not ‘guesswork’ but the result of thousands of studies, spanning the majority of the previous century.
Despite this, there are some who still doubt if these changes are really man-made. While concentrations of carbon dioxide have changed according to natural cycles in the past, the changes observed at present are very different. Following the industrial revolution, atmospheric measurements have shown a massive rise in carbon dioxide at a rate unprecedented in all of earth’s history, and the amount of emissions is still rising to this day. This increase is so large that the concentration of carbon dioxide today is greater than it has been in over 400,000 years. But could this be the result of a natural process?
Studies have shown that there is no link between long-term natural cycles (which usually take thousands of years) and the climate change we’re experiencing today (which has happened over a few decades).
Furthermore, the observed changes in temperature follow a very similar trend to those observed for rising carbon dioxide concentrations. In 2013, John Cook et al. revealed that 97 per cent of scientists agree that humans are the direct cause of global warming. This value is the result of an analysis of nearly 4,000 scientific papers that specifically mentioned the cause of climate change, and numerous studies that followed agreed with this assessment.
Nowadays, complex computer programmes simulate the climate of our planet over many decades to determine several possible outcomes of the ongoing trends in climate change. To account for the uncertainties that this process tends to produce, many institutions around the world use different variations of these programmes and combine the results, thereby getting a broad picture of the possibilities. I am currently part of a team of international scientists running these programmes and studying what they produce.
The most commonly mentioned consequences of climate change are “warmer climates” and “sea level rise”, but possibly one of the most dangerous is a change in extreme events.
These are rare events that can severely disrupt a nation and possibly cost lives. Notable examples in Malta include the Mediterranean tropical-like cyclone of November 2014, the heatwave of July 2017 and the storm (possibly a ‘bomb’ cyclone) that hit last February.
Many studies reveal that the frequency and intensity of these events are increasing throughout the world and will continue to do so for some time. Following the example mentioned at the beginning of this article, these are the ripples in the pond.
We have become complacent and choose not to act, often using the excuse, “we are too small to make a difference”. As members of a species that manipulates its surroundings in order to survive, humanity has explored and populated the entire planet and continues to push the boundaries of scientific discovery. To assume that the actions of over 7.6 billion people have no consequence on our surroundings is naive at best and irresponsible at worst. We are selfishly destroying our own habitat for (temporary) comfort and profit.
We need to do everything in our power to push towards a greener economy. We have known about this problem for over a hundred years now and time is running out. As a changing climate starts to challenge the infrastructure of our nation, how long will it take to reach the breaking point? Do we wait for one or more major natural disasters to start taking this seriously? Will we reach a point where we become refugees?
If we wait until the problem becomes more apparent than it already is, it’s going to be too late.
Dr James Ciarlò is a Post-Doctoral Fellow with the National Institute of Oceanography and Applied Geophysics (OGS), in collaboration with the Earth System Physics section (ESP) of the Abdus Salam International Centre for Theoretical Physics (ICTP) in Trieste, Italy.
This is a Times of Malta print opinion piece