The Earth’s cryosphere – the places where water freezes into ice and snow – are shrinking due to human activity. These changes affect everything from how we live to what we eat. They also impact the environment around us, including the air we breathe, the food we grow, and even the health of our oceans.
Changes to our oceans and cryospheric systems are having global consequences for nature and people. We’re already seeing more frequent and intense storms, widespread coral reef bleaching and rising sea levels.
The Ocean Is Getting Warmer
Earth stores 90% of our extra energy in the oceans. But we are seeing a rise in temperatures that could damage marine life.
Scientists say climate change is affecting the ocean — and it’s getting warmer faster than scientists thought. As water warms up, it expands. This causes sea levels to rise, putting coastal areas at risk. And rising seas threaten many species that live near shorelines.
Ocean heat waves are becoming more common. In fact, one study says about half of all extreme weather events are now tied to global warming. Scientists say we must act quickly to avoid damaging ecosystems.
The Ice Sheets Are Shrinking
In recent decades, ice sheets around the world have been melting due to global warming, causing sea levels to rise. But now a study published in Nature suggests that some of the ice is actually shrinking. If confirmed, it could mean that sea levels are rising even faster than expected, and that we’re already seeing signs of climate change.
Researchers analyzed data collected over the past three decades from NASA satellites. They found that glaciers in Greenland had lost about 40 billion tons of ice per year since 2002, while those in West Antarctica had shrunk by 30 billion tons annually. Overall, the volume of ice stored in the Antarctic and Greenland regions combined has decreased by about 200 cubic kilometers each year.
As part of the study, researchers looked at how much water was being absorbed into the ocean from rivers flowing out of the region. In both cases, they found that the amount of freshwater entering the oceans increased during the period studied. This finding supports previous research suggesting that melting ice sheets are contributing to rising sea levels.
Sea Level Is Rising
The world is experiencing extreme events like never before. A recent study found that there are now more extreme weather events occurring globally than ever before. There are several reasons why we are seeing more extreme weather events. One reason is climate change. Another is human activity. Increased urbanization and development has led to more people living closer together. This increases the amount of heat trapped by cities and leads to increased temperatures. Climate change contributes to rising sea levels. And it makes storms stronger. Storm surges are becoming larger due to the warmer oceans. Sea level rise is increasing worldwide. Scientists say that global average sea level rose about 7 inches over the last century. But, there is some good news. Some areas around the globe are already adapting and preparing for the effects of climate change. In 2017, coastal communities around the world adopted plans to adapt to rising seas. These include building barriers and raising roads. They are also creating strategies to protect against storm surge.
Ocean Acidification Is Increasing
The oceans are becoming less alkaline. Carbon dioxide levels in seawater are rising because of human activity, causing the waters to absorb more CO2. As a result, pH levels are dropping. This has implications for marine life, including coral reefs, shellfish and plankton. In fact, it is already having effects on some species. For example, oyster larvae are developing more slowly under high CO2 conditions. And according to one study, sea turtles that live near shorelines are experiencing slower growth rates and lower survival rates. Another study found that fish eggs incubated in warmer water produced fewer offspring.
Rapidly Changing Oceans and Cryosphere
Rapidly Changing Oceans and Cryosphere The Intergovernmental Panel on Climate Change (IPCC), which produced the landmark report, says it is virtually certain that the world’s oceans have been heating up for some time now, and that those changes are likely to continue into the future. In addition, the report finds that there is high confidence that human activities are responsible for most of the observed increase in global average surface temperature since 1950.
Among the report’s findings about oceans is that “it is virtually certain that over the 21st Century, the global ocean is projected to transition to unprecedented levels of warmth,” with increases in ocean heat content, ocean circulation patterns, and atmospheric water vapor concentrations.
As the oceans warm, the IPCC reports, melting ice caps could cause sea levels to rise dramatically and threaten low-lying areas such as New York City, Miami Beach, Venice, Amsterdam, London, Shanghai, Tokyo, Mumbai, and many others.
In addition, the report finds evidence that the oceans are absorbing much of the extra heat trapped by greenhouse gases, leading to greater ocean acidity and dissolving more carbon dioxide from the atmosphere. As a result, the amount of CO2 dissolved in the oceans is expected to double by 2100, compared to preindustrial times. This process is known as ocean acidification.
Other effects of the accelerated warming of the seas are already occurring, including coastal flooding, coral bleaching, and increased frequency of severe storms.
Our Ocean and Cryosphere Under Threat
While many of these impacts right fully make it into front-page headlines, climate change is also fundamentally affecting parts of our planet that we don’t understand well—the ocean and the cryosphere.
The September 2019 release of the International Panel on Climate Change’s Special Report on the Ocean and Cryosphere in a Changing Climate(SROCC),produced by more than 100authorsfrom36countries,is a sobering analysis of current conditions as well as the projections into the future.
Produced by more than100 authors from 36countries, the SROCC pain stakingly reviews thelatestscientificliteraturereferencingsome7,000scientificpapersinall.