The lack of food also means that bears cannot build up the fat and energy reserves they need to get through the months in which they don't eat. The long periods of starvation also affect the ability of bears to reproduce. If polar bears were forced to spend five or six months on land without food, it will be difficult for them to survive. Young cubs, pregnant or nursing female bears, and old bears are especially vulnerable to starvation with a lengthening of the ice free season. Scientists have pointed out that some arctic regions, for example the islands of the Canadian Arctic are especially prone to losing their bear populations. It has been estimated that two-thirds of the world's polar bear population, some 20,000 to 25,000 animals, will be gone by the year 2050. Predictions of an ice free summer Arctic Ocean by the end of the century may mean that little, if any, habitat remains for polar bears, threatening the survival of the species. Without sea ice to support their usual lifestyle, polar bears may become more common on land. They may be forced to try to hunt inland rather than on the ice. At the same time, newcomers such as grizzly and brown bears may explore the increasingly warming Arctic and could come into contact with these ice bears. Polar bears and browns bears can interbreed and their breeding season in fact coincides. However, normally they do not interbreed, even if their territories overlap, because they are physically separated. Polar bears out on the sea ice and brown bears on land. Though polar and brown bears have been crossed in zoos, such hybrids have only recently been reported from the wild. The first one was documented in 2006 in Canada. Four years later, genetic testing on another hybrid confirmed the origin of the bear stemming from a grizzly, and grizzly-polar hybrid parents. The name for these hybrids has been suggested as Nanulak. This comes from combining the Inuit names for polar bear, nanuk, and grizzly bear, aklak. This question will require speculation based upon many of the aspects which had been touched on in the course. Which of the following do you think might lead to an irregular availability of wild caribou or reindeer for an Arctic community? A, increased winter rainfall making it difficult for caribou to forage. B, changed migration routes due to seasonal scarcity of food. C, changed migration routes due to increased numbers of biting insects. D, warm temperatures make reindeers' behavior unpredictable. More than one answer might be correct, so check all that you think apply. Answers A, B, and C are all reasons why caribou or reindeer might become irregularly available to Arctic communities. Under normal circumstances, warm temperatures alone do not change caribou behavior. Unlike polar bears, caribou are not directly dependent on sea ice, they spend their lives on land. Though they will use sea ice to migrate between islands, if they live within an archipelago or coastal setting. However climate change in the Arctic is not limited to ocean environments, as we have already seen. One of the effects of climate change is increased rainfall rather than snowfall due to warmer air temperatures. If rain falls on existing snow on the landscape, it can seep through the snow cover and into the underlying soil, forming an ice layer over the tundra. This ice can encrust the vegetation to such a degree that animals, like the caribou, cannot get to the food they depend on, lichen and mosses. Additionally, even if the ice is thin enough to be broken by hooves, the underlying vegetation may be infected by mold and fungi, making it toxic. Other more extreme weather events associated with changing climate will affect caribou, raising mortality in the species. Blizzards may cause deaths during the winter. Hot summers may cause heat-related deaths because caribou have very effective insulating fur layers and few sweat glands. Warmer temperatures may also bring more pests into the Arctic. This may also extend the season of biting and parasitic insects which harass the reindeer. These insects affect their behavior as well as causing a deterioration of their health. Changing vegetation patterns, unstable ground conditions caused by changing climate and melting permafrost will profoundly affect the migration routes caribou take. These routes are used by the caribou to move between their birthing grounds and winter grounds. These changes will put stress on the species, further impacting their resilience and health. As Arctic climate is warming, new species like deer and moose may invade the region. They will compete for food and habitat, forcing caribou to shift their range. We already saw that industrial pollutants can be transported into the Arctic via the atmosphere and accumulate in the Arctic food chain. Sulfur dioxide, a pollutant produced by coal burning industrial activities, can kill the lichen that caribou eat. Mercury can be absorbed by lichen, subsequently accumulating in caribou that eat it. A large part of the reindeer population is semi-domesticated and closely tied to humans. Consequently, reindeer herding will be impacted by climate change as well. Close contact between humans and reindeer may increase the chances of infection with zoonotic diseases, those diseases that are carried by and transmitted by animals. For example, the stresses caused by changing climate may make reindeer herds more susceptible to infection with Brucellosis. This bacterial disease causes disruption and disorders in the reproductive system for the animals. It can also be transmitted to humans by meat and milk consumption. Unlike wild reindeer and caribou, domesticated herds may be better able to adapt as a result of management by humans, particularly in the Sami regions of Fennoscandia. You can learn more about reindeer herding and management strategies in the Arctic culture and Arctic economies MOOCs. Under a warmer global climate, extreme weather events, both warm and cold, occur throughout temperate latitudes. Which of the following do you speculate are true? A, there are stronger pressure, temperature and moisture gradients, which drive more extreme events worldwide. B, climate change results in unpredictable impacts from place to place. C, climate change is a myth as it is not based on scientific facts. D, climate change only affects some regions on the planet but not others. More than one answer might be correct so check all that you think apply. Answers A and B are correct. With more energy in the climate system, there are stronger climatic gradients, which lead to more intense and often extreme weather events, as were seen in Europe and the United States in 2012. All parts of the world are affected by climate change, but not everywhere is affected equally or in the same fashion. The projected changes in Arctic environments will impact the rest of the world because of how tightly connected the Earth's climate system is. This means that more southerly latitudes situated far from the Arctic will experience some of the consequences of the changing Arctic. For example, temperate latitudes may experience unusually cold or rainy weather due to the polar jet stream meandering farther south than usual. This was the case in 2012 when Europe was in the grasp of the coldest winter temperature recorded in 26 years. Air temperatures in central Europe plummeted as low as minus 40 degrees Celsius. At the same time, most of North America enjoyed a warmer and much dryer winter than usual. This was followed by an unusually warm spring and a summer heat wave for much of the continental U.S. In fact, 2012 was declared the second most extreme year on record in terms of precipitation, temperature, and the number of tropical storms making landfall. Though the effects of the changing Arctic climate will be felt farther south, the most severe impact will be felt by the four million people that live in the Arctic. These shifts will be especially pronounced for indigenous cultures which depend on traditional ways of life. Changing Arctic environments will certainly have serious effects on human health. This can be a challenge for Arctic peoples who rely on the environment for their livelihood and sustenance. For example, the changing climate will probably make some traditional foods irregularly available or even unavailable with sea ice and permafrost changes and changes in snow cover. There may be increased difficulty in accessing hunting or fishing grounds, or altered animal migration routes. In turn, this may mean that more people have to shift from a traditional diet of country food to imported food that may be dramatically less healthy. Many available food items are often processed or preserved food varieties. This is in part due to the challenge of reliably shipping fresh food. Such processed food has been linked to poor health outcomes, including diabetes, heart disease, and tooth decay. This also exposes remote communities to the high price of imported food, often a result of the cost of transporting goods over long distances. Our next section is going to examine issues related to health, pollutants, and food security. Speculate on which of the following strategies might best help Arctic residents who rely on a subsistence diet, to minimize their intake of pollutants while maintaining a healthy diet. Why these are a particular concern in the Arctic will be discussed next. A, eat a varied diet of different country foods as much as possible. B, become a vegetarian to avoid pollutants in meat. C, hunt and fish elsewhere in the world and bring the food back to the Arctic. D, eat only processed food imported from elsewhere. Only answer A is correct, as the reasonable strategy to minimize intake of pollutants for those on a subsistence diet. Vegetarianism is often not feasible for many Arctic residents due to the difficulty obtaining fresh produce. Similarly, it can be difficult to maintain a healthy diet from processed food. Hunting and fishing elsewhere doesn't always prevent exposure to pollutants, and it prohibitively expensive for most Arctic residents. Even now, where traditional animal-based foods are available, some contain high levels of contaminants. For example, persistent organic pollutants, or POPs, are transported to the Arctic by the atmosphere and the oceans. These chemicals also accumulate in marine mammals, as well as fish. Under present conditions, national health agencies often set recommended maximum consumption levels to prevent pollutants reaching toxic levels in humans. The production of some POPs has decreased in the twenty-first century. Even so, with the possibility of POPs being remobilized, with the melting of permafrost and glacier ice. Those who rely on traditional animal-based foods, will have to remain watchful of their diets for the foreseeable future. We've seen that climate change will probably increase the risks of living a subsistence lifestyle in the Arctic. Can you think of useful adaptations to help deal with new and unpredictable conditions? A, use of new weather reporting and predicting technology to better understand weather conditions before they happen. B, stay at home and avoid the weather as much as possible. C, use educational resources to better understand the risks. D, hunt and fish elsewhere in the world where conditions are safer. More than one answer might be correct, so check all that you think apply. Answers A and C are useful adaptations. Many Arctic communities are already using technology and various information to better adapt to changing conditions. The physical effects of the changing Arctic climate on human health include the many risks inherent in going out on the land. It includes the dangers of physical injury because of sea ice or ground conditions. In particular, with more extreme warm and cold weather event, people who rely on sea ice to travel and hunt, now face conditions they may not have experienced before. On thin or unusual sea ice, there is an increased risk of becoming trapped on the sea ice, and an increased chance of drowning. Traveling Arctic coastal waters by boat can also be more dangerous. In the summer in many arctic communities there's more open water, bigger waves and sudden and unpredictable weather changes. Physical risks also encompass the ill effects of increasingly warm weather including heat stroke. Ozone depletion has led to increase ultraviolet radiation reaching the Earth's surface. This is hazardous to human health with effects ranging from sunburn to cataracts and even skin cancer. A warming climate in the Arctic also opens up the door to new bird and insect species arriving from temperate latitudes. This increases the chance of arctic residents catching new diseases. For example, the West Nile Virus is carried by birds and transmitted to humans by mosquito bites. Based upon everything you have heard about the Arctic so far, which of the following factors might contribute to mental health issues in the Arctic that may not always apply in the urbanized world? A, Arctic communities are often in remote locations far from the opportunities common in other parts of the world. B, winters are long and sometimes there is very little to do, especially during periods of 24 hour darkness. C, given the current isolation, adaptation to climate change is impossible. D, rapid changes in environment and climate have coincided in changes in culture over the past century. More than one answer might be correct, so check all that you think apply. Answers A, B and D could contribute to mental health issues in the Arctic. Climate change adaptation isn't impossible. And in fact, many people in the Arctic are finding practical adaptations to deal with their changing environment. Human health does not just encompass physical well being, but extends to mental and social health as well. The changing environment puts stress on Arctic inhabitants beyond the immediate physical effects of changing climate, because Arctic cultures and lifestyles are often closely tied to the land and environment. Changes in or the loss of traditional lifestyles may be felt more acutely in the Arctic than in more urbanized environments. Stressors can include the changes in activities such as going out on the land and hunting of food and the loss of some related cultural practices, but also as Arctic communities adapt and modernize new factors such as unemployment are emerging. Such cultural shifts can impact psychological health and can be expressed as feelings of alienation, marginalization or hopelessness. Northerners are at higher risk of mental health issues, such as depression, anxiety, substance abuse. And in the worst case, even suicide. Strategic adaptations and investments can help address these issues, but are not always a solution unto themselves. The overall warming trend that has been observed in the last few decades in the Arctic is unprecedented and beyond what is transmitted through traditional knowledge. Diminishing sea ice, melting permafrost and shifting animal migration routes are all new phenomena as are extreme unseasonal weather events, increased precipitation and new species arriving from the South. All these changes represent threats to the traditional way of life for the many indigenous peoples of the Arctic. Released in 2005, the Arctic Climate Impact Assessment was carried out by over 300 scientists from around the world and guided by the Intergovernmental Arctic Council and the nongovernmental International Science Committee. Using IPCC methods, the ACIA evaluated the effects on and consequences of Arctic climate change for the environment, people and ecosystems. Despite the sometimes frightening predictions of Arctic climate change, the ACIA found that adaptation is possible and even likely to occur for most arctic residents. In particular, the ACIA noted that arctic peoples are highly resilient and very adaptable to changing conditions. The research into adaptation strategies is still relatively young. Several studies have highlighted possible strategies and coping mechanisms in which Arctic communities can lessen the sometimes grave impacts of shifting environments. Not all Northerners are experiencing the same changes or even at the same rate, but there's already good reason to expect that Arctic indigenous cultures and communities are ready and capable of adapting to changing climate. As an example, the Sami of Northern Fennoscandia have adopted state of the art equipment and techniques to manage reindeer herding. This includes global positioning systems or GPS, geographical information systems or GIS, precision climate monitoring and other modern technologies. The Sami supported by the national governments of Norway, Sweden and Finland have also begun to pursue increased educational opportunities for their people in order to maintain traditional culture and livelihoods, even under a changing climate. Other indigenous groups are doing likewise. That brings us to the end of our MOOC on the changing Arctic. We certainly hope you've enjoyed yourself and gained an appreciation for the Arctic, but this isn't the end. There are three more Arctic MOOCs. Have you wondered about the lives and cultures of the people of the North? Or about resource and traditional economies of the Arctic? Have a look at our MOOCs on Arctic peoples and cultures, Arctic research and development and Arctic economies. [MUSIC]
