A Global Perspective on Global Warming
Our planet continues to experience warming, consistently setting new ‘record temperatures’ each year. Are we merely skimming through the news, experiencing momentary concern, and then carrying on with our lives as usual? Or do we truly grasp the implications of rising temperatures, understanding what they may – and inevitably will – result in? It’s time to initiate meaningful changes in our lives to address and mitigate these consequences.
A report, published in October and prepared by 13 researchers led by renowned ecology professor William J. Ripple of the University of Oregon, begins as follows: “Life on planet Earth is under siege. We are now in an uncharted territory. For several decades, scientists have consistently warned of a future marked by extreme climatic conditions because of escalating global temperatures caused by ongoing human activities that release harmful greenhouse gasses into the atmosphere. Unfortunately, time is up.” Apart from these heart-warming sentences, the study also reveals the following: The highest temperatures in history were recorded during June-August 2023, temperatures were more than 1.5 degrees Celsius above pre-industrial levels for a total of 38 days until September, Antarctic glaciers have shrunk to their lowest known levels, annual global coal consumption reached its highest level in history in 2022, and despite all this, humanity has shown minimal effort to combat climate change.
Another recent article, by James Hansen, the US scientist who issued the first ever warning about the greenhouse effect in the 1980s, and more than a dozen colleagues predicts that the world is heating faster than is currently understood and this will result in a key temperature threshold being breached as soon as this decade, becoming almost 2°C hotter by 2050. Another study by Anders Anker Bjørk and his colleagues from University of Copenhagen, who have been studying the changing glaciers of our planet for a long time, paints a similarly worrisome picture. Analysing satellite imagery and 200,000 old photographs, the research group found out that global warming has accelerated the melting of Greenland’s glaciers fivefold in the past 20 years. Greenland’s ice sheets contain so much water that if they melt completely, sea levels will rise by at least 6 metres.
Rising temperatures and rising sea levels will lead to a decrease in the oxygen content of the oceans and an increase in acidity levels, which will affect the vitality of the oceans and seas. In April of this year, researchers announced that the oceans were the warmest they had been since 1982. And they have been warming much faster than we expected. This increase in temperature is also affecting the algae living in the oceans. Almost 5 years ago, it was announced that regional colour changes had started to occur in the seas based on satellite images and that this could be at least partly due to the increase in temperature. Changes in the distribution of algae can have serious consequences for the balance in the existing food chain.
Not only are the ice caps in polar regions at risk of melting; the 2019 report from the International Centre for Integrated Mountain Development (ICIMOD) emphasised the vulnerability of glaciers in the Hindu Kush-Himalayan Mountains. Researchers project that between 36% and 75% of these mountain glaciers may vanish by 2100 due to global warming. The anticipated repercussions include heightened occurrences of extreme climate events and floods, disruptions to monsoon rainfall patterns, a severe blow to agriculture, and consequently, a significant shortage of water, food, and energy for cities in the region.
An ecosystem is defined as the entirety of all living species in a given area and the non-living components such as soil, water, and air with which these species interact. In this context, rising temperatures exert significant negative impacts on ecosystems at large. Many species have evolved to specific temperatures and climatic conditions throughout their evolutionary history. Their behavioural patterns, especially in terms of reproduction and feeding, have been finely tuned to the conditions in areas where they have been distributed for thousands of years. Temperature is one of the most crucial of these conditions. As average annual temperatures shift, species that have adapted to certain temperature ranges will face a dilemma: either extinction or moving to new habitats. The fortunate ones may successfully make it –provided they can find suitable new habitats. Meanwhile, the distribution of native species, endemics, and other closely related species will undergo changes. Notably, the range of disease vectors like mosquitoes and ticks will also expand.
However, less mobile species may struggle to relocate swiftly enough to new suitable habitats, jeopardizing the continuation of their generations. Plants, in particular, face significant challenges. The timing of crop planting and harvesting will be disrupted, leading to diminished yields. Water scarcity and deteriorating soil conditions will intensify due to increased evaporation, resulting in heightened erosion. While the immediate concern may be high-value economic crops (it has been nine years since we published the news announcing that the world’s coffee plantations would be halved by 2050 due to climate change), the endangerment of one plant after another will impact the animals that depend on them, the predators of these animals, and ultimately, humans. In essence, biodiversity will suffer a severe blow, triggering an inevitable domino effect with ecosystems collapsing successively.
Perhaps some of you will think of the “Global Seed Vault” in Svalbard. This facility serves as a seed bank, housing millions of seeds collected from all corners of the world, ready to germinate -a last line of defence against biodiversity loss. However, even this vault is under threat. While regulations are consistently implemented to shield seeds from the impact of rising temperatures, these regulations may prove insufficient over time, potentially leading to the unintended germination of our global emergency seeds in the Arctic.
One vital biological fact to consider is the proteins. These large, complex molecules consisting of amino acid chains are essential for all organisms as they make up the majority of enzymes and hormones, and are critical for the structure and functioning of many organelles -including the cell membrane, ribosomes, mitochondria, and chloroplasts. All proteins require specific temperature ranges to function properly. One very significant effect of heat on proteins is denaturation. Heat may break the chemical bonds that give a protein its specific shape, destroying its three-dimensional structure and, as a result, its biological function. Even if the temperature is lowered after denaturation, the protein may not regain its original structure and function. The temperature at which denaturation occurs varies among different proteins. Some proteins denature at relatively low temperatures, while others are more heat-stable.
A research published in Nature in August has found that the photosynthetic machinery of some tropical trees have already started to break apart due to heat. The study reports that even when the surrounding air is cooler than the leaves themselves, around 0.01 percent of individual leaves in tropical trees can reach a critical temperature at which the enzymes required for photosynthesis to go through denaturation. Although this may sound as a relatively minute proportion, for now, the loss of enough leaves on a tree may result in the death of the entire tree. Through experiments and models, the team figured out the temperature at which photosynthesis generally stops in a tropical tree’s leaf: around 46.7°C. For trees found at higher latitudes, this temperature is similar but a little lower. They also found that a tipping point could occur when local average temperatures rise by about four degrees. As photosynthesizing leaves naturally cool the surrounding air, their death will also mean a more rapid temperature rise in the neighbouring leaves. Another cascade effect…
The impact of urbanisation on wildlife is being exacerbated by rising temperatures, particularly in arid cities with limited vegetation. A comprehensive scientific study, led by a team that includes Prof. Dr. Çağan Şekercioğlu and his Ph.D. student, utilising camera trap data from 725 different locations in North America, sheds light on the situation concerning mammals. Several other studies yield similar findings for insects, fish, amphibians, reptiles, and birds.
It is high time for us as individuals to take responsibility. Decision-makers at various levels in many countries have initiated crucial measures. We hope to see a swift increase in the number of such actions, leading to effective initiatives and regulations addressing this issue on several levels -from our daily life habits to economic activities, and from urban planning to scientific research.
REFERENCES
- 1. https://www.researchgate.net/publication/374975790_The_2023_state_of_the_climate_report_Entering_uncharted_territory
- 2. https://www.reuters.com/business/environment/greenland-glaciers-melt-five-times-faster-than-20-years-ago-2023-11-10/
- 3. https://www.eea.europa.eu/signals-archived/signals-2019-content-list/articles/soil-land-and-climate-change
- 4. https://www.epa.gov/climateimpacts/climate-change-impacts-forests
- 5. https://www.scientificamerican.com/article/tropical-forests-may-be-getting-too-hot-for-photosynthesis/
- 6. https://attheu.utah.edu/research/warming-temperatures-make-life-even-tougher-for-urban-wildlife/