THE CONSEQUENCES OF CLIMATE CHANGE

Global climate change has already had observable effects on the environment. Glaciers have shrunk, ice on rivers and lakes is breaking up earlier, plant and animal ranges have shifted and trees are flowering sooner.

Effects that scientists had predicted in the past would result from global climate change are now occurring: loss of sea ice, accelerated sea level rise and longer, more intense heat waves.

Scientists have high confidence that global temperatures will continue to rise for decades to come, largely due to greenhouse gases produced by human activities. The Intergovernmental Panel on Climate Change (IPCC), which includes more than 1,300 scientists from the United States and other countries, forecasts a temperature rise of 2.5 to 10 degrees Fahrenheit over the next century.

According to the IPCC, the extent of climate change effects on individual regions will vary over time and with the ability of different societal and environmental systems to mitigate or adapt to change.

The IPCC predicts that increases in global mean temperature of less than 1.8 to 5.4 degrees Fahrenheit (1 to 3 degrees Celsius) above 1990 levels will produce beneficial impacts in some regions and harmful ones in others. Net annual costs will increase over time as global temperatures increase.

“Taken as a whole,” the IPCC states, “the range of published evidence indicates that the net damage costs of climate change are likely to be significant and to increase over time.”

Dirtier air

Rising temperatures also worsen air pollution by increasing ground level ozone, which is created when pollution from cars, factories, and other sources react to sunlight and heat. Ground-level ozone is the main component of smog, and the hotter things get, the more of it we have. Dirtier air is linked to higher hospital admission rates and higher death rates for asthmatics. It worsens the health of people suffering from cardiac or pulmonary disease. And warmer temperatures also significantly increase airborne pollen, which is bad news for those who suffer from hay fever and other allergies.

Higher wildlife extinction rates

As humans, we face a host of challenges, but we’re certainly not the only ones catching heat. As land and sea undergo rapid changes, the animals that inhabit them are doomed to disappear if they don’t adapt quickly enough. Some will make it, and some won’t. According to the Intergovernmental Panel on Climate Change’s 2014 assessment, many land, freshwater, and ocean species are shifting their geographic ranges to cooler climes or higher altitudes, in an attempt to escape warming. They’re changing seasonal behaviors and traditional migration patterns, too. And yet many still face “increased extinction risk due to climate change.” Indeed, a 2015 study showed that vertebrate species—animals with backbones, like fish, birds, mammals, amphibians, and reptiles—are disappearing 114 times faster than they should be, a phenomenon that has been linked to climate change, pollution, and deforestation.

More acidic oceans

The earth’s marine ecosystems are under pressure as a result of climate change. Oceans are becoming more acidic, due in large part to their absorption of some of our excess emissions. As this acidification accelerates, it poses a serious threat to underwater life, particularly creatures with calcium carbonate shells or skeletons, including mollusks, crabs, and corals. This can have a huge impact on shell-fisheries. Indeed, as of 2015, acidification is believed to have cost the Pacific Northwest oyster industry nearly $110 million. Coastal communities in 15 states that depend on the $1 billion nationwide annual harvest of oysters, clams, and other shelled mollusks face similar long-term economic risks.

Higher sea levels

The Polar Regions are particularly vulnerable to a warming atmosphere. Average temperatures in the Arctic are rising twice as fast as they are elsewhere on earth, and the world’s ice sheets are melting fast. This not only has grave consequences for the region’s people, wildlife, and plants; its most serious impact may be on rising sea levels. By 2100, it’s estimated our oceans will be one to four feet higher, threatening coastal systems and low-lying areas, including entire island nations and the world’s largest cities, including New York, Los Angeles, and Miami as well as Mumbai, Sydney, and Rio de Janeiro.

OCEAN ACIDIFICATION

Climate Change isn’t the only consequence of carbon pollution from fossil fuels. If driving global temperature rise wasn’t enough, increased carbon in our atmosphere is also behind the rapid acidification of our world’s oceans.

But what exactly is ocean acidification?

When carbon dioxide (CO2) is absorbed by seawater, chemical reactions occur that reduce seawater pH, carbonate ion concentration, and saturation states of biologically important calcium carbonate minerals. These chemical reactions are termed “Ocean Acidification” or “OA” for short.

Oceans becoming more acidic after the Industrial Revolution are no accident. As humans burn more and more fossil fuels, the concentration of carbon dioxide in our atmosphere continues to rise, driving climate change and making both air and sea temperatures hotter and hotter.

Ocean acidification is expected to impact ocean species to varying degrees. Photosynthetic algae and sea grasses may benefit from higher CO2 conditions in the ocean, as they require CO2 to live just like plants on land. On the other hand, studies have shown that a more acidic environment has a dramatic effect on some calcifying species, including oysters, clams, sea urchins, shallow water corals, deep sea corals, and calcareous plankton. When shelled organisms are at risk, the entire food web may also be at risk. Today, more than a billion people worldwide rely on food from the ocean as their primary source of protein. Many jobs and economies in the U.S. and around the world depend on the fish and shellfish in our oceans.

Ocean acidification is an emerging global problem. Over the last decade, there has been much focus in the ocean science community on studying the potential impacts of ocean acidification. Since sustained efforts to monitor ocean acidification worldwide are only beginning, it is currently impossible to predict exactly how ocean acidification impacts will cascade throughout the marine food chain and affect the overall structure of marine ecosystems. With the pace of ocean acidification accelerating, scientists, resource managers, and policymakers recognize the urgent need to strengthen the science as a basis for sound decision making and action.

Future predictions indicate that the oceans will continue to absorb carbon dioxide and become even more acidic. Estimates of future carbon dioxide levels, based on business as usual emission scenarios, indicate that by the end of this century the surface waters of the ocean could be nearly 150 percent more acidic, resulting in a pH that the oceans haven’t experienced for more than 20 million years.

CLIMATE CHANGE IMPACTS ON MARINE LIFE

Sometimes it’s surprising on how self-centered we humans can be. We are so concerned about our future; we forget to think about others present. When I say others, I mean Marine life.

We all are aware about changing climate and how it is affecting our lifestyle. We all are also aware that these are results of our own actions.

But we close our eyes towards the living being who are suffering because of our actions.

Much attention has been focused on the effects of climate change on forests, farms, freshwater sources and the economy. But what about the ocean?

This June, the world’s oceans reached 17 degrees Celsius, their highest average temperature since record keeping for these data began in the 19th century. And a new experiment suggests that those balmier waters might mean big changes for the marine food chain.

Even with its vast capacity to absorb heat and carbon dioxide, the physical impacts of climate change on the ocean are now very clear and dramatic. According to a 2013 report, temperatures in the shallowest waters rose by more than 0.1 degree Celsius (0.18 degree Fahrenheit) each decade between 1970 and 2010.

Most marine species and ecosystems are presently under numerous simultaneous threats. In addition to climate change, these include fishing, elevated UV exposure, pollution, alien introductions and disease. The resistance of individual species to single threats may be reduced in the face of multiple stressors, and perturbed ecosystems suffer diversity loss that can compromise ecosystem function and resistance to further change. For instance, drops in pH may interfere with ion exchange, depressing metabolism and leading to a narrower window of thermal tolerance. Polar bears are not only struggling in the face of ice loss, but are also weakened by accumulation of polychlorinated biphenyls; the Black Sea suffered a regime shift after prolonged heavy fishing pressure, a jellyfish invasion and eutrophication; many coral reefs are suffering from rising temperatures, acidification, disease, fishing and tourist impact as well as silting and excess nutrients from river runoff. Analysis of several north Atlantic fish stocks suggests that declining recruitment is climatically-driven, and that fishing on its own cannot explain observed downward trends. The claim that “climate findings let fishermen off the hook” does not, however, tell the whole story, and excessive fishing will certainly not assist ecosystems stressed by climate change. There is growing acceptance of the requirement for an ecosystem approach to marine fisheries and environment management: this approach should take account of the whole gamut of anthropogenic and natural threats to ecosystems, including climate change.

The changing climate and its effect on marine life have a direct impact on us. As coral reefs die, we will lose an entire ecological habitat of fish. According to the World Wildlife Fund, a small increase of two degrees Celsius would destroy almost all existing coral reefs. Additionally, ocean circulation changes due to warming would have disastrous impacts on marine fisheries.

This drastic impact is often hard to imagine. It can only be related to a similar historical event. Fifty-five million years ago, ocean acidification led to a mass extinction of ocean creatures.

According to our fossil record, it took more than 100,000 years for the oceans to recover. Eliminating the use of greenhouse gasses and protecting our oceans will prevent this from reoccurring.

CLIMATE CHANGE LEADS TO CORAL BLEACHING

Coral reefs are one of the most diverse ecosystems on this planet. They are home to numerous species of marine life and offer a plethora of benefits both to natural ecosystems and to the human population. Coral reefs bring in enormous funds to coastal countries through tourism, fishing, and discoveries of new biochemicals and drugs (Hoegh-Guldberg 1999). Additionally, they provide natural coastal protection and building materials (Hoegh-Guldberg 1999). However, coral reefs are experiencing massive die-outs all around the world.

Climate change is the greatest global threat to coral reef ecosystems. Scientific evidence now clearly indicates that the Earth’s atmosphere and ocean are warming, and that these changes are primarily due to greenhouse gases derived from human activities.

Climate change will affect coral reef ecosystems, through sea level rise, changes to the frequency and intensity of tropical storms, and altered ocean circulation patterns. When combined, all of these impacts dramatically alter ecosystem function, as well as the goods and services coral reef ecosystems provide to people around the globe.

Warmer water temperatures brought on by climate change stress corals because they are very sensitive to changes in temperature. If water temperatures stay higher than usual for many weeks, the zooxanthellae they depend on for some of their food leave their tissue. Without zooxanthellae, corals turn white because zooxanthellae give corals their color. White, unhealthy corals are called bleached. Bleached corals are weak and less able to combat disease.

Bleaching events on coral reefs around the globe were observed in 1998 (West and Salm 2003). In some Pacific islands, a little bit of bleaching is common in the summer; however, there have been times when bleaching is particularly bad in this region (Craig 2009). For example, larger than normal bleaching events in the National Park of American Samoa occurred in 1994, 2002, and 2003 (Craig 2009). As climate change continues, bleaching will become more common, and the overall health of coral reefs will decline.

MELTING DESERT

Climate change is turning Antarctica green. It may conjure up an image of a pristine white landscape, but researchers say climate change is turning the continent green.

Antarctica’s ice may melt faster than previously thought as result of a newly discovered network of lakes and streams that destabilize the continent’s ice shelves, according to new research — making them more vulnerable to collapse.

Because the collapse of vulnerable parts of the ice sheet could rise the sea level dramatically, the continued existence of the world’s great coastal cities — Miami, New York, Shanghai and many more — is tied to Antarctica’s fate.

Antarctica holds 90% of the world’s ice and rapid ice melt and the associated collapse of ice sheets could have profound effects across the globe, including a steep rise in sea levels, but much remains unknown about the speed at which Antarctic ice is melting. An accompanying study also published in Nature this week evaluates a specific region in Antarctica — the Nansen Ice Shelf — and finds that the worst destabilizing effects are avoided as the melted water drains into the ocean. It remains unclear which ice sheets will respond like Nansen and which will have the destabilizing effect seen elsewhere.

Ice sheets flow downhill, seemingly in slow motion. Mountains funnel the ice into glaciers. And ice flowing from the land into the sea can form a floating ice shelf.

A rapid disintegration of Antarctica might, in the worst case, cause the sea to rise so fast that tens of millions of coastal refugees would have to flee inland, potentially straining societies to the breaking point. Climate scientists used to regard that scenario as fit only for Hollywood disaster scripts. But these days, they cannot rule it out with any great confidence.

Countries around the globe committed in the 2015 Paris Agreement to work to keep temperatures from rising more than 2°C (3.6°F) by 2100, though it remains unclear whether they will be able to meet that target. Even if that target is met, sea level rise will average 0.2 meters (0.67 feet) by 2100, though many places like the East coast of the U.S. will face a far greater rise, according to recent research.