Earth’s polar caps quickly losing ice. Coral reefs bleaching to a chalky white. Stronger storms devastating islands and cities, claiming lives and destroying homes. Those aren’t claims of what our world faces in a warmer future. Those climate change impacts are already happening — and due to worsen.
Already, glaciers and ice sheets are shrinking. Some are disappearing super fast. The Greenland ice sheet lost an average 278 billion tons of ice per year from 2006 to 2015. That amount of water alone is enough to cause average global sea levels to rise about 7.7 millimeters (0.3 inch) a decade.
More dramatically, on July 31 a record-breaking 57 percent of that ice sheet showed signs of melting. Meanwhile, the Antarctic ice sheet has been losing an average 155 billion tons per year.
Glaciers from the Himalayas to Chile and Canada have seen big melts. Together, they’re losing another 220 billion tons of ice per year. Melt water from these glaciers today slakes the thirst of millions of people and their crops. If those glaciers disappear — and many are starting to — their downstream communities could become very thirsty.
In nature, biodiversity is a combination of biological entities that are interacting. Climatic conditions regulate species distribution. Biodiversity is important to the health of the Earth’s ecosystems and thus a precondition for life on the planet. It boosts immunity and the adaptability of the species, which enables some particular species or ecosystems to adapt more quickly than others to changing circumstances. With climate change, biodiversity is decreasing.
Image from Wikimedia Commons
In section 1.1, we learned about the levels of biological organization. Starting with the organism, there are levels up until the biosphere. With individuals affected due to climate change, the balance of organisms in an ecosystem will also change. There are many reasons as to why a specific species may have to change and adapt to a new habitat. Global warming, drought, floods, deforestation and land use changes are amongst the leading factors. Different species require different temperatures and altitudes to survive. For example with land species, rising temperatures cause species that favor cooler climates to begin move north. In areas where temperatures are cooling, species that prefer warmer temperatures need to adapt to a different climate as well. This can have implications depending on the species as this new range and can remove vital predators or prey that are crucial to maintaining the food chain in that area.
Similarly with aquatic species, as sea levels rise, freshwater and salt water systems may start mixing thus relocating many organisms. For example, as temperatures increase, the habitat ranges of many North American species are moving north and to higher elevations. In recent decades, in both land and aquatic environments, plants and animals have moved to higher elevations at a median rate of 36 feet (0.011 kilometers) per decade, and to higher latitudes at a median rate of 10.5 miles (16.9 kilometers) per decade. While this means a range expansion for some species, for others it means movement into less hospitable habitat, increased competition, or range reduction, with some species having nowhere to go because they are already at the top of a mountain or at the northern limit of land suitable for their habitat. These factors lead to local extinctions of both plants and animals in some areas. As a result, the ranges of vegetative biomes are projected to change across 5-20% of the land in the United States by 2100.