It was the evening when my family and I watched 'An Inconvenient Truth' together that drove me to think about the climate change that is taking place as of now. The movie got me to think about how much of an effect global warming has on the population of many species and human beings. Global warming is now the biggest threat to Earth and the survival of many living things.It is a major cause of the climate change. To the people who don't know what is, it basically is the increase in the Earth's temperature. The main reason of global warming is the green house effect, which is when the sun's radiation gets trapped in the Earth's atmosphere. This has caused a major change in the climate, impacting the lives of many species. Global warming has had a greater effect on the population of polar bears for many years bacause the Arctic temperatures are rising many times faster than anywhere else on the planet!
Because of the exposure to too much of the sun's radiation, the ice in the Arctic is melting. As a result, the polar bears are forced to swim longer distances. The average weight of a mature female has dropped from 650 to 507 pounds because of this change in the climate. This decrease in the weight of mature females has led to leaner cubs. As a result, many of the cubs can't survive the harsh conditions in their environment. There have been many happenings over the past few years that suggest the extinction of polar bears. For example, in the year of 2004, researchers from the U.S. Minerals Service found four polar bears drowned in the Beaufort Sea. Polar bears are known to be notoriously strong swimmers and travel long distances between ice floes. The researchers reasoned that the polar ice cap had floated a record 160 miles north of the Alaskan coast. This meant that the bears were forced to swim longer distances than they usually had to.
Not only has global warming affected the population of polar bears in the Arctic, it has also affected the cues many animals relied upon to match the climate. The European blackcap birds cite as an example of this phenomena. These birds would typically breed in Germany, and then migrate to Spain and Portugal for the winter. Because of global warming, the climate in Spain and Portugal has become unsuitable for these birds in the winter. So instead of migrating to Spain and Portugal for the winter, some of these birds migrate to the west of England where the climate is suitable. This helps the British birds to beat their Spanish cousins to Germany to breed. With this said the British birds in turn get better nesting sites than their Spanish cousins. This east-west migration has now become embedded in the British birds' genes. So, what does this example prove? You may ask. Well, this proves that global warming is altering the optimal time for temperature-sensitive activities without changing the daylight cycle in any given place.
You probably want to know now if any of the species present today have started to evolve. The answer is yes, but first what is evolution? Evolution is a change in a kind of organism over time. This is exactly what has happened to many small animals as of now. Scientists believe that many of the species of animals have changed genetically over time to adapt to rapid climate change. Because many smaller animals breed quickly, such as squirrels, birds, and insects, they are showing some signs of changes in their behavior to increase their chances of survival. Scientists also believe that the genetic adaptations will have to cope with the length of seasons compared to the rapid changes in summer temperatures. On the other hand, larger animals are believed to have a longer and more difficult time evolving genetically to adapt to their changing environment because they are slower in reproducing compared to smaller animals. This also because smaller animals typically have short and rapid life cycles compared to larger animals. Studies prove that over the past few decades, rapid climate change has led to heritable genetic changes in animal populations. Examples include the Canadian red squirrels which have reproduced earlier this year. Also, the northern American mosquitoes who live in water-filled leaves of carnivorous plants and can adjust their life cycles to shorter more 'southern' day lengths.
Not only are land animals in danger of extinction, but many sea animals are in danger of becoming extinct. Whales and dolphins are the biggest of the sea animals that have a chance of becoming extinct. The factors that might lead to the extinction of these sea animals are the changes in sea temperature, declining salinity because of the melting ice and rainfall, the sea level is rising, there is a loss of icy polar habitats, and the decline of krill population in key areas. Krill is a tiny shrimp-like animal that is dependent on sea ice and it is the main source of food for many of the great whales. Since the ice cover is decreasing, there will be more human activities in the Arctic, such as commercial shipping, oil, gas, and mining exploration and development. This can dramatically hurt these sea animals greatly. Whales and dolphins are known for adapting to new environment, but the problem is how easily they can adapt to global warming and the changing temperature of the sea waters.
In the future, I believe that the polar bears will become extinct because of the Arctic ice melting. In addition, the line between the polar bears and the grizzly bears is vanishing. Because of this, the grizzly bears are now entering the polar bears' territory. This is not only causing tensions between the two types of bears, but it is also creating cross-breeds between the two bear.
I also believe that the whales and the dolphins have a chance of becoming extinct, mainly because the sea level temperatures are rising. Also, because the food the whales depended on are diminishing. Humans, I think, have a chance of evolving both of technological factors and environmental factors. However, I believe that the technological side may play a bigger role for humans to adapt to the changing climate. Even though there might be much extinction of species, I believe that with evolution many species will have a better chance of survival.