Global Warming / Climate Change / Ocean Acidification

Global warming is the increase of the average temperature in the atmosphere and oceans over time due primarily to human influences.

Updated by Eirini Kardara

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Terms, definitions & interaction

What is ocean acidification? To put it simply ocean acidification is the decrease of the pH in the seawater. This decrease in pH is caused by carbon dioxide / CO2 (mainly due to emissions in the atmosphere) dissolving in seawater.

There is a direct connection between ocean acidification and global warming, which will be described thoroughly in paragraphs below. However, first we should clarify what ‘global warming’ means. Global warming is the increase of the average temperature in the atmosphere caused by several factors. It should not be confused with the term climate change. The term “global warming” is used to refer to an accelerated rise in average global temperatures caused by human activity while “climate change” is most often used in association with changes in climate with no easily identifiable cause, such as the processes that produced the Ice Ages.

Global warming

The fact that the world – including the atmosphere and ocean, etc. are getting warmer is more than obvious nowadays. The evidence can be seen around the globe through a series of impacts including increases in the frequency and severity of wildfires, extreme weather systems and rising water temperatures. Although the Earth naturally undergoes changes in climate the severity and speed of current shifts cannot be attributed to natural rhythms but must be recognized as exclusively due to human intervention. Undoubtedly without the impact that human activities cause in the present, our oceans would be imperiled by the wide array of issues that endanger their health.

According to NASA’s Goddard Institute for Space Studies (GISS), the average global temperature on Earth has increased by a little more than 1° Celsius (2° Fahrenheit) since 1880. Two-thirds of the warming has occurred since 1975, at a rate of roughly 0.15-0.20°C per decade.

The above numbers might seem small or insignificant, given that our planet is vast with various local climates across the world. However, it should be noted that the global temperature record represents an average over the entire surface of the planet. While temperature fluctuations at a local level can easily be explained by natural factors and were mostly within a normal range for some past generations, global temperatures cannot.

Why are global temperatures rising? The Earth is heated by solar radiation from the Sun. The amount of energy absorbed by the Earth and how much solar radiation is reflected back into space affects the average global temperature. The chemical composition of the atmosphere plays a key role in determining how much solar radiation is reflected back into space. Gases in the atmosphere including water vapor, carbon dioxide, methane, nitrous oxide and ozone are known as greenhouse gases.  “Greenhouse gases” are so named because they trap radiant energy from the sun that would otherwise be radiated back into space. Increases in some of these greenhouse gases leads to the creation of a “heat trapped cloud” and thus significant temperature rises across the globe.

greenhouse effect

Atmospheric CO2

The chemical composition of these greenhouse gases is affected by what we as human are “giving to the atmosphere”. Industry, agriculture, transport and personal contributions including home heating, electrical and personal transport play a key role in Earth’s rising temperatures.

The greenhouse gas theory started in the 19th century when the Swedish chemist and 1903 Nobel Laureate, Svante Arrhenius, determined that increases in greenhouse gas concentration would lead to higher global mean temperatures, while decreases would lead to colder global mean temperatures. His finding was a result of his research on ice ages and was largely rejected by his peers at the time. A colleague of Arrhenius, Arvid Högbom, was one of the first scientists to study the carbon cycle. Arrhenius used his data to base his assessment that in 1890, emission and absorption of CO2 in the atmosphere were roughly in balance, and that burning fossil fuels would not cause problems. However, this was based solely on the use of coal, not on the use of fossil fuels in the automobile and other industries. It should also be noted that his studies did not account for the impact of agricultural emissions such as methane (CH4), the loss of carbon sinks and the effect of losing the solar radiation reflecting ice cover of the poles.

A one-degree global change is significant because it takes a vast amount of heat to warm all the oceans, atmosphere, and land by that much. Please note a one- to two-degree drop was all it took to plunge the Earth into the Little Ice Age.

The Kyoto Protocol was developed by the United Nations Framework Convention on Climate Change (UNFCCC) as an international agreement to reduce greenhouse gas emissions worldwide. The Protocol was entered into force in February 2005, and signed by countries committed to reducing CO2 emissions and 5 other greenhouse gases. They may also engage in emissions trading, or the purchase of credits from other countries that remain under the limits of greenhouse gas emissions. In this way, countries that may exceed the limits can still comply with the protocol. To date, 192 countries have ratified the agreement.

global warming

Global climate change has been studied on a large scale based on analyses of global temperature fluctuations over thousands of years; for example, since the last Ice Age, which occurred approximately 12,000 years ago, global temperatures have been relatively stable. Studies on a smaller scale, however, show that temperatures in the lower troposphere have increased between 0.08 and 0.22°C per decade since 1979. Still, these modern day changes are not always linear, which has created a source of debate within the scientific community and the news media.

The study of paleoclimatology (ancient climates) is increasingly linked to modern day climate study. For example, the Earth was in an ice age for the last 160,000 years prior to the end of the last Ice Age. Earlier studies of this time period showed little variability in temperatures; however, more recent studies showed the variability to be about twice as great as previously published, indicating that temperature fluctuations are more frequent throughout time than first thought. However, this does not negate the impact of human activity on the current rate of global warming.

Natural factors such as changes in the Earth’s orbit around the Sun, solar activity, and volcanic emissions may contribute but cannot account for the severity and rate of change. Science is increasingly pointing to human activities as the reason that global warming is accelerating.

human fingerprints

Source: IPCC report 2007

The Impacts of Global Warming on Ocean Life

Global warming may also impact ocean life and life on earth by altering the ocean’s circulatory patterns and the flow of surface currents and local areas of upwelling and downwelling, which can affect nutrient and oxygen delivery over large areas. As Arctic ice melts, it dilutes the deep nutrient-rich ocean currents that move throughout the Atlantic and reduces their ability to sink, a process necessary for the normal circular path of these deep currents which transfers 85% of the world’s heat around the world. If melting continues at an alarming rate, the Atlantic Ocean’s ability to maintain the weather as we know it might collapse. Giant storms, breeding in unstable conditions, could grow in intensity and numbers as they pummel the coastlines of Northern Europe and North America.

Scientists at Scripps Institution of Oceanography at the University of California, San Diego, and their colleagues have produced the first clear evidence of human-produced warming in the world’s oceans, a finding they say removes much of the uncertainty associated with global warming.

Even in the past decade there has been signs of climate change such as in Canada’s Gulf of St. Lawrence. There was not enough ice to provide necessary habitat for thousands of baby harp seals, and nearly 100% of all pups born this year (2019) drowned with direct implications for polar bears who rely on the seal pups as a key food source. In Tasmania over the past 50 years, 20-80% of the east coast kelp forests have disappeared as they’re surrounded by warmer, nutrient-poor waters. Scientists recently predicted that Australia’s Great Barrier Reef, the only biological structure that can be seen by the naked eye from space, will be virtually dead within 30 years. As mentioned earlier, Arctic polar bears are facing extinction due to dramatic reductions of Arctic ice, a problem that will also threaten all Arctic wildlife. These terrible events, as they say, are merely the tip of the iceberg.

Bigger, more terrifying events are taking place. For example, corals are already under serious threat right now due to “bleaching” caused by the seas growing warmer. A coral is a living animal but 80% of its energy is generated by photosynthesis via tiny algae within its body known as zooxanthellae. If environmental conditions change, the coral’s defense is to expel the algae, which results in death of the coral. But this is not the only “hot water” corals face.

Ocean acidification

Scientists have discovered that the basic chemistry of the ocean is being altered by excess carbon dioxide absorption, which threatens marine organisms by increasing acidification. Acidification is caused by a reaction between CO2 and H2O, which forms carbonic acid (H2CO3). Carbonic acid increases the acidity of ocean waters by lowering the pH which inhibits the reaction organisms (e.g., coccolithophores – one of the most abundant phytoplankton in the ocean, corals, foraminifera, echinoderms, crustaceans, and some mollusks, especially pteropods) use to secrete skeletal structures and shells made of calcium carbonate (CaCO3). With increasing acidity, every marine species that constructs skeletons and shells of CaCO3 will find it more difficult to survive in the future. The impact of such a widespread decline in shell-producing marine organisms could be disastrous for nearly all ocean ecosystems. Increasing acidity will also undoubtedly affect numerous reproductive and/or physiological processes in other marine species with unknown consequences.

Human Impact on Climate Change

Whether or not the planet is warming at accelerated rates, likely caused by human activity, is no longer a topic of debate. The data can no longer be disputed.

The terms “global warming” and “climate change” are used interchangeably. However, “global warming” implies the warming of our planet due to a direct human influence while “climate change” is more accurately used to describe changes in climate due to natural fluctuations, such as the processes that produced the Ice Ages.

The scientific evidence in support of global warming continues to mount and the media is increasingly highlighting the topic to inform us of the very real dangers involved in global warming. Common media images include polar bears that are no longer able to find enough ice to survive and often drown in search of food. Glaciers in the Arctic and Greenland are breaking apart at unprecedented speed, causing sea levels to rise. The ocean’s temperature is rising; as a result, we are witnessing marine species forced to migrate from habitats they have lived in for at least thousands of years in search of more hospitable areas.

Recently, some island nations and communities have actually begun evacuation procedures as rising seas flood their homes and land. Rising sea levels caused by the expansion of sea water as it warms and the melting of glaciers has caused a one mm increase in sea level, which translates to a shoreline retreat of about 1.5 m. This has been seen in the U.S. along the Atlantic Coast where erosion has narrowed beaches and washed out houses. In other countries, such as the Tuvalu Islands in the Pacific, communities are planning their moves as their homelands are slowly submerged. Other currently threatened nations include the Cook and the Marshall Islands, where one island (Majuro) has lost up to 20% of its beachfront already.

One of the most visible impacts of global warming is the increase in the intensity and frequency of extreme weather events. The National Climate Assessment finds that the number of heat waves, heavy downpours, and major hurricanes has increased in the United States, and the strength of these events has increased as well ( Floods, Flush floods, Tornadoes, Heavy snowfall, heatwaves,) leading to loss of lives, properties, erosion having a huge impact in the local economies.

Billion-Dollar Extreme Weather Events, 2000-2019 in the following link:

All these changes, whether we recognize it or not, are connected to us. Anything that happens to the ocean will affect our lives. Between half and three-quarters of the world’s population live within 60 km of the sea which will be driven inland by rising sea levels. All major cities will be filled up with unimaginable congestion; food and water supplies will dwindle, good relations will break down; housing will be unavailable; homelessness and poverty will become overwhelming. And this could happen in 20 years or less. And we will feel the impact in other ways as well.

Global warming will make memories out of many living things, and as we remember the bounty of life that this planet used to support, we will feel shame and a deep sense of loss, unless we do everything we can to slow climate change, protect what is left, and restore at least part of what we have lost.

However, little of this has to come to pass, yet. We can protect the future by realizing that no one is born a conservationist. A conservationist is shaped and inspired by world events: these events, changes happening to our world. Human beings have always been at their best when things are at their worst. We can no longer wait for the worst to come before we reveal what is best within us. Now is the time to step up.

What we can do

There is a series of things people can do in order to face as much as possible this atmosphere & ocean threat, starting from daily routine activities:

  1. Reduce plastic production and pollution. Plastic pollution is an issue in and of itself but the burning of plastic waste and the energy used in producing and recycling plastics all contribute to greenhouse gases. Remember the 6 Rs: Rethink, Refuse, Reduce, Reuse, Repair, Recycle. Think of alternatives where you can, choose options with less plastic, use less plastic in your life, reuse the plastic you do use – avoid single use plastics, where possible repair plastic items and if you do have to dispose of plastic then try to ensure it is recycled.
  2. Reduce your transport footprint. Try walking or cycling, use public transport or car share. If you can afford to invest in electric cars then do so. If one third on the planet was following this tactic, we would have 65% less emission in the atmosphere.
  3. Reduce your house footprint. If you are able to invest in green energy solutions such as solar panels, solar boilers, double glazing, insulation etc. These are not only good for the planet but over time can save you money.
  4. Protect and regenerate carbon sinks. Help to conserve forests, seagrass beds, soils and other carbon sinks. Where you can get involved and help plant trees let them absorb CO2 instead of it getting trapped in the aforementioned heat trapping cloud.
  5. Search, investigate & participate on sharing the news. Be active for NGOs, of for yourself, follow the latest news on climate change and become a rebel to today’s passive situation.

These few things, if they were to be applied by a significant percentage of the world’s population would be life changing. Our planet (land & ocean) have many secrets yet to reveal, why not try to save them and become heroes for the next generation?

Last but not least, it’s worth mentioning the impacts of COVID-19. This pandemic has had a great personal cost and dreadful impact on people the world over yet it also offers us a chance.

We’ve never had a better chance to make a greener world. Covid-19 has put a pause on industry and interrupted normal life. Now the big question is whether we can capitalize on this moment.

In a few months, the demand for energy has reduced dramatically. According to the International Energy Agency, the global energy consumption will be 6% less this year, equivalent to losing the entire energy demand of India. Can we use this breathing space to re-imagine how we conduct ourselves in the future and at the same time save our planet?

Scientists at Woods Hole Oceanographic Institution have been studying climate change for decades. Considerable information about the oceans and climate change is available at: The Institution held a panel discussion to address questions about climate change. The discussion was introduced by Terry Joyce, director of the Ocean and Climate Change Institute and a senior scientist in physical oceanography, and moderated by Tom Wheeler, chairman of the corporation.

Ocean acidification due to increasing atmospheric carbon dioxide – 30 Jun 2005 – The Royal Society

If you haven’t watched An Inconvenient Truth yet, we highly recommend it.

Additional References

Center for Investigative Reporting | PBS Frontline
Climate Change Impacts on the United States
The Potential Consequences of Climate Variability and Change
By the National Assessment Synthesis Team, US Global Change Research Program Published in 2000

Boiling Point: How Politicians, Big Oil and Coal, Journalists and Activists Are Fueling the Climate Crisis—And What We Can Do to Avert Disaster By Ross Gelbspan
Everyone should read this book if you’re interested in the future of civilization.

A few random quotes from Gelspan’s book:

“Many activists today are promoting the use of energy-efficient light bulbs, carpooling, and other climate-conscious lifestyle changes. Unfortunately, these strategies, even under the most wildly optimistic scenarios, fall far short of nature’s requirement that we cut our consumption of coal and oil by 70 percent.”

“Our climate is capable of immense and wildly disruptive surprises. Every day, those surprises seem progressively more likely than not. Not only are we gambling with our future, we are gambling with our eyes blindfolded. We can’t even see the cards we’ve been dealt.”

“Although the disappearance of the glaciers is visually striking, its importance may be overshadowed by a less visible but more pervasive consequence of atmospheric warming. All over the world, species are traveling toward the poles in an effort to maintain temperature stability.”

“There is only one chance in 100 that the rate of warming will be less than double the warming rate of the last 100 years—and a 99% probability that it will exceed double the past warming rate…. The most likely estimate of warming between [now] and 2100 is 5.5°F. This is five times the warming rate experienced over the past 100 years. At the high end, there is a five percent chance that the warming could be more than eight times the warming rate of the past century.”

“In this immense drama of uncertain outcome, this much is true: A major discontinuity is inevitable. The collective life we have lived as a species for thousands of years will not continue long into the future. We will either see the fabric of civilization unravel under the onslaught of an increasingly unstable climate—or else we will use the construction of a new global energy infrastructure to begin to forge a new set of global relationships.

If we are truly lucky—and visionary enough—those new relationships will differ dramatically from what we have known throughout our recorded history. They will be based far less on what divides us as a species and far more on what unites us. Embedded in the gathering fury of nature is a hidden gift—an opportunity to begin to redeem an increasingly fragmented world. The alternative is a certain and rapid decent into climate hell.” Get the book (~$5 used) here: Boiling Point

See 101+ Things We Can All Do to protect our environment, hopefully slow global warming and protect our ocean.

North Carolina Wishes Away Climate Change
Disappearing world: Global warming claims tropical island
Global Warming & Rising Oceans by Jeffrey Chanton, Ph.D., Department of Oceanography, Florida State University
How Did Humans First Alter Global Climate? by William F. Ruddiman, Ph.D. – A bold new hypothesis suggests that our ancestors’ farming practices kicked off global warming thousands of years before we started burning coal and driving cars.
Defusing the Global Warming Time Bomb – Global warming is real, and the consequences are potentially disastrous. Nevertheless, practical actions, which would also yield a cleaner, healthier atmosphere, could slow, and eventually stop, the process – by James Hansen – Science & Technology at Scientific American.
Climate Models Reveal Inevitability of Global Warming
Intergovernmental Panel on Climate Change (IPCC)
Wikipedia: Global Warming
An Abrupt Climate Change Scenario and Its Implications for United States National Security – October 2003 (PDF)
United Nations Framework Convention on Climate Change
Major Climate Report Describes a Strong Risk of Crisis as Early as 2040 – By 2050, rising temperatures exacerbated by human-induced belches of carbon dioxide and other greenhouse gases could send more than a million of Earth’s land-dwelling plants and animals down the road to extinction.
World of Change: Global Temperatures – Earth Observatory/NASA

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