Ecosystems Feel the Heat from Climate Change

Today is 75 degrees and sunny. Tomorrow’s weather looks cloudy with a chance of rain. Expect cooler temperatures over the weekend. You can turn on the TV or open an app to see the daily weather forecast. Weather — which includes temperature, rain, snow, wind, and humidity — varies from day to day.

Climate is a bit different. Climate is the average weather in a place over long periods of time. It looks at changes in weather patterns over years.

Throughout history, Earth’s climate has warmed and cooled. Geological records show the Earth has experienced seven ice ages and warming periods. Scientists believe dramatic climate shifts caused a mass extinction around 252 million years ago. Volcanoes erupted and spat out huge amounts of lava and gas. The gasses were absorbed into Earth’s atmosphere and held in the heat. Temperatures rose. Oceans warmed. Oxygen in the oceans decreased quickly and killed up to 96% of ocean life.

So if our Earth’s climate has changed before, what is the big deal now? For the first time, human activity is causing the Earth to warm.

Causes of Climate Change

Our Earth is wrapped in a blanket of gasses. Just as you snuggle under a blanket to stay warm on a chilly evening, Earth’s blanket — called the atmosphere — keeps the planet warm. As sunlight passes through the atmosphere, the gasses trap heat from the sun. Without the atmosphere, Earth would be too cold to sustain life.

But over the last hundred years, the Earth’s atmosphere has trapped too much heat. Humans depend on fossil fuels like oil, gas, and coal to power our lives. They heat our homes, fuel our cars, and run factories that process food and make all the products we buy on Amazon with a click of a button. Burning fossil fuels releases a gas called carbon dioxide into the atmosphere. Carbon dioxide traps more heat inside the atmosphere. Imagine being wrapped in a heavy, unbreathable blanket. Are you feeling hot and sweaty yet?

With more trapped heat, the Earth is warming up. Scientists concluded that over the last 100 years Earth’s temperature increased 1.5 degrees Fahrenheit. This may seem small, but temperatures are rising twice as fast as they did 100 years ago. And scientists forecast that temperatures will continue to grow, increasing 2.5 to 10 degrees Fahrenheit in the next 100 years, according to NASA.

Impacts of Climate Change

Warming temperatures have far-reaching impacts: oceans warm, glaciers melt, sea levels rise, and even the chemistry of the ocean changes. With such shifts, organisms — and whole ecosystems — feel the impact.

Warming Oceans

The Great Barrier Reef’s yellow, red, and fuchsia corals stand out against the ocean’s blue backdrop. Schools of fish, equally as colorful as the reef, swim in and out of coral. Named one of the seven natural wonders of the world, the Great Barrier Reef sits off the coast of Australia and is the most extensive reef in the world. According to the World Wildlife Fund (WWF), it is home to 1,500 species of fish, 411 types of coral, 134 species of sharks and rays, and six kinds of sea turtles.

But the reef’s breathtaking beauty is being white-washed. Earth’s oceans absorb heat stored by carbon dioxide in the atmosphere. This warms the ocean’s water, and corals feel stressed. Under stress, microscopic algae that live in the coral make chemicals that hurt the coral. In response, the coral kicks out the algae. Without the algae, the coral loses its brilliant colors and turns ghostly white. This is called coral bleaching. Although not yet dead, bleached coral can starve and is more vulnerable to diseases. In 2016, the Great Barrier Reef lost over 680 miles of coral to bleaching, according to the WWF.

Bleaching also threatens all the organisms that depend on coral for shelter and food. For example, the bright yellow butterflyfish eats the coral’s mucus-like exterior layer. Gross, right? But as corals bleach and some die, the butterflyfish loses its slimy food source.

Melting Ice Caps

Warming temperatures caused by climate change are most extreme in the Arctic. Scientists report that the Arctic has warmed twice as fast as the rest of the world, according to the BBC. As temperatures increase, sheets of ice and glaciers that cover this northernmost part of the world melt.

The small yet plump ringed seals depend on Arctic ice for survival. They carve dens in the ice and snow where they mate, give birth to pups, and seek protection from predators. But as the ice melts, ringed seals’ dens collapse, and seal pups suffer the most. Typically, mother seals nurse and care for their pups for six weeks after birth. Collapsing dens leads to pups being prematurely separated from their mothers. Scientists have observed more seal pup deaths due to a warming climate.

In the Arctic ecosystem, the loss of seals impacts other Arctic creatures that rely on them for food. With a melting habitat and less food, polar bears must roam long distances to find food. This uses up bears’ energy and burns the fat needed to survive in the Arctic. Scientists worry that without seals, polar bears could be too hungry and weak to produce healthy cubs.

Rising Sea Levels

Sea turtles lay their eggs on beaches’ sun-warmed sands. During the nesting season, sea turtles emerge from the water and scuttle across the beach to dig nests. Turtles lay between 60 and 180 eggs in sandy holes. Some turtles nest every year while other species only nest every nine years.

But climate change threatens sea turtles as sea levels rise. Rising sea levels have two causes: more water being added to the ocean as Arctic ice melts and the expansion of water as it heats up. NASA reports that in the last 140 years, sea levels rose by 8 to 9 inches and have grown by .14 inches each year since 2006. Rising sea levels erode beaches and threaten to wash away turtle nests. Losing the next generation of turtles could lead some marine turtles closer to extinction.

Sea turtles are a keystone species which means removing turtles would disrupt the whole ecosystem. Hawksbill turtles clean up coral reefs which are homes to many fish. Leatherback turtles keep jellyfish populations under control. Green turtles graze on seagrasses and keep them healthy for smaller organisms that live hidden in the grasses’ waving arms.

Acidic Waters

Each day, the ocean absorbs 22 million tons of excess carbon dioxide made from burning fossil fuels according to Smithsonian. That’s nearly the weight of two gigantic anchors on cruise ships. Absorbing gasses helps out the atmosphere but dooms the ocean. As the sea dissolves carbon dioxide, the water becomes more acidic.

More acidic oceans disturb the ocean ecosystem. Higher levels of acid dissolves shells on clams, oysters, and scallops, and with no protection, these shellfish die. Shellfish are a popular food in the ocean. Fish feast on them, starfish use powerful arms to open their shells and enjoy the tender innards, birds pick up shellfish and crack open their shells. More acidic oceans also destroy corals that marine organisms call home. Ocean ecosystems feel the impact of climate change.