Global warming: Effects, causes and measures, a snapshot in 2021

Earthzineclimate change

Scientists worldwide are meticulously studying global warming to uncover further updates on the state of global warming and its consequent effects.

7 Mar, 2022

Afzalbek Fayzullaev

Global warming is a term that is tossed around in all spheres of our lives; from political agendas to company pledges to posts made on social media, global warming seems to become more of a pressing matter each passing second. However, global warming is not simply the Earth getting hotter, but a multitude of complex issues, each more concerning than the next.

Fig. 1: Sources of greenhouse emissions [3]

Fig. 1: Sources of greenhouse emissions in the US [3].

Global warming occurs when CO2 (and other heat-trapping gases such as methane, nitrous oxide, water vapor and chlorofluorocarbons) get released in the atmosphere and absorb sunlight and solar radiation that have bounced off the earth’s surface [1]. These pollutants trap this heat and thus cause the Earth’s temperature to rise. Human activities have undoubtedly contributed significantly to this change [2].

According to Figure 1, data from the Inventory of U.S. Greenhouse Gas Emissions and Sinks reported that 29% of all U.S. Greenhouse Gas Emissions came from transportation, and close behind 25% came from electricity, with industry trailing in third. All these sectors rely heavily on the use of nonrenewable sources of energy such as coal, oil, or natural gas. Such fossil fuels are not only finite in number, meaning we will run out of them at some point, but also “produce large quantities of carbon dioxide when burned” [4] To add to this, the use of fossil fuels is also connected to a myriad of other negative effects such as land degradation, water pollution, ocean acidification, and even exposing millions of people to harmful carcinogens [4].

Related Stories

Sustaining Long-Term Ocean Observations

The challenges of deep-sea exploration

Ocean Decade – Regional Planning Workshop for Northern/Central Indian Ocean countries and ROPME sea area

New Website Brings Deep Ocean Exploration Imagery and Lessons to Educators and Public

Effect on the World and its Inhabitants

Scientists worldwide meticulously study global warming continuously to uncover updates on the state of global warming and its consequent effects, which is a key first step in trying to avoid the world plunging into the abyss of possible effects from global warming. One example of regular scientific updates resulting from global-scale assimilation of climate knowledge, is the reports from the Intergovernmental Panel for Climate Change (IPCC).

Melting Ice

According to the Artic Report Card, a report made about the status of the environmental changes in the Artic, “Even if we significantly curb emissions in the coming decades, more than a third of the world’s remaining glaciers will melt before the year 2100. When it comes to sea ice, 95% of the oldest and thickest ice in the Arctic is already gone” [5]. Since the industrial revolution, human activities have emitted so much greenhouse gases that the effect on glacial ice is unfortunately irreversible. Figure 2 shows an example of this where areas that were once covered in ice, are now barren ground.

To highlight this urgency, it is even seen that “if emissions continue to rise unchecked, the Artic could be ice free in the summer as soon as the year 2040” [5]. This in turn would lead to the rise in sea levels and coastal lines in all parts of the world.

Figure 2:

Figure 2: The Arctic has been the hotspot of global climate change effects so far, and Arctic glaciers are melting at increasingly higher rates.

Sea Levels and Ocean Acidification

The rising of sea levels is caused by two factors, the melting of ice sheets and glaciers but also by the fact that the volume of the ocean is expanding as water becomes warmer [6]. When ocean water gets warmer, the water eventually will expand and so cover more land. This is a harsh causal cycle where ice melts into water because of warmer global temperatures and the water then expands due to the existing warmer climate.

A climatologist from Princeton, Michael Oppenheimer, further emphasized the urgency of this situation by stating how “an event that used to cause severe flooding once a century, we’re going to get that same water level once a year” [7]. He also further went on to speak about how there is almost no possible way to stop sea level rise in this century. Even with severe cuts in fossil fuel burning, there will continue to be a measurable increase in ocean levels.

“In the last decade (from 2008-2017), we’ve dumped into the atmosphere about 40 gigatons of emissions of heat-trapping gases each year from the burning of fossil fuels and land-use change—or the equivalent to 252 million blue whales.” [8]

An especially difficult aspect of the consequences of global warming is the fact that one issue will cause a cascade of other problems [2]. For instance, this rise in sea levels can cause “destructive erosion, wetland flooding, aquifer and agricultural soil contamination with salt” [8]. Not only does land become contaminated, but the oceans also become much more acid because of the absorption of CO2 emission, a phenomenon called ocean acidification. Ocean acidification is a real threat to the survival of marine species; Acidification reduces the availability of carbonate ions in ocean water causing animals that build their shells from calcium carbonate to have a much lower chance of survival [9].


Global warming effects have equally harmed nature and land species as well. Massive raging fires have erupted in all parts of the world. In places such as Greece, California and Turkey, fires have become much more frequent [9]. According to an article published in September 2020, “increasing heat, changing rain and snow patterns, shifts in plant communities, and other climate-related changes have vastly increased the likelihood that fires will start more often and burn more intensely and widely” [10]. Fires are also becoming much more intense and harming more land and animals than ever.

Another example of the impact is that on bees. They had already been facing the harmful effects of climate change, however because of recent events, “increasing numbers of bees species can be classified as vulnerable or endangered as a direct result of fires” [11]. To add to that, fires in Australia also “killed at least 5,000 koalas—as much as a third of the state population—and that the fires destroyed 24 percent of koala habitat on public lands” [12]. The detrimental effects of fires are becoming more and more drastic, and in the process harming more animals.

Koalas are under severe threat because their habitats are being destroyed by increasingly destructive fires.

Cautious outlook on the Future with a Beam of Hope

This trickle-down of consequences can last much longer. Burning of fossil fuels leads to several problems with each causing even more issues. This causal cycle makes reversing the problems of global warming especially difficult for there is no one solution that works in all categories.

Greta Thunberg, an 18-year-old environmental activist from Sweden, recently had a keynote address about the lies surrounding climate change initiatives. She called out political leaders from all around the world and commented that their courageous words that were backed up by no action: “Build back better. Blah, blah, blah. Green economy. Blah blah blah. Net zero by 2050. Blah, blah, blah” [12] she said in this speech in Italy. Thunberg is referring to the commitments made by countries during the Paris Agreement. During this conference, countries agreed to “communicate actions they will take to reduce their Greenhouse Gas emissions” as well as submit “long-term low greenhouse gas emission development strategies” [13]. She was pointing out how countries are not taking action to achieve these goals. She proceeded to end this speech with inspiring words for a brighter future: “We can no longer let the people in power decide what hope is. Hope is not passive. ... Hope is telling the truth and taking action. And hope always comes from the people.” [14]

On the positive side, the recent “Conference of the Parties” or COP26 seemed to indicate that world leaders all around the world are still concerned about global warming. During this conference, 120 world leaders came together and reaffirmed their goals in the Paris Agreement as well as added new deals and announcements. Some of these new implementations included 137 countries that “took a landmark step forward by committing to halt and reverse forest loss and land degradation by 2030” as well as over 100 countries aiming to “limit methane emissions by 30 per cent by 2030” [15]. Leaders all around the world are continuing their efforts and even making new goals for them to collectively strive for.

As bleak as the future may seem, action is being taken by people from young activists to world leaders. May it be spreading awareness or signing new policy into effect, the urgency of global warming is seemingly becoming clear to many. These people become a beam of hope so that generations of the future will be able to fully enjoy the oceans, animals, and life of our planet.

[1] “Global Warming 101”, NRDC: Amanda Macmillan, Jeff Turrentine
[2] “Climate change widespread, rapid and intensifying”, Intergovernmental Panel on Climate change,
[3] “Sources of Greenhouse Gas Emissions”, EPA United States Environmental Protection Agency:
[4]” Fossil Fuels: The Dirty Facts”, NRDC: Melissa Denchak,
[5]” Why are glaciers and sea ice melting”, WWF World Wildlife Fund: Lorin Hancock,
[6] “Climate Change: Global Sea Level”, science & information for a climate-smart nation, Rebecca Lindsey,
[7] “Sea level rise is speeding up, says Princeton climatologist Michael Oppenheimer”, Princeton University, Liz Fuller-Wright,
[8] “CO2 and Ocean Acidification: Causes, Impacts, Solutions”, Union of Concerned Scientists,
[9] “Seal level rise, explained”, National Geographic, Christina Nunez,
[10] “Wildfires rage across Greece, Turkey, Italy, Spain, Russia and Lebanon”, The Washington Post, Staff,
[11] “The science connecting wildfires to climate change”, National Geographic,
[12] “Wildfires contributing to the great bee decline”, Courthouse News Service, Dustin Manduffie,
[13] “The Paris Agreement”, United Nations Climate Change,
[14] “Blah, blah, blah: Greta Thunberg lambasts leaders over climate crisis”, The Guardian, Damian Carrington,
[15] “COP26: Together for our planet”, United Nations Climate Change,

Image attributions:

"artic glacier" by Vishnu V (licensed under CC BY-NC-SA 2.0)
"Koala" by flyinglester is licensed under CC BY-NC 2.0