permafrost thawing that releases methane - strong greenhouse gas. improving forecasting systems is important to solve the problem. in view of the risks, wmo has created a vegetation fire and smoke pollution warning and advisory system for forecasting fires and related impacts and hazards across the globe. wmo's global atmosphere watch programme has released a short video about the issue. invasive species in forests an invasive species is any kind of living organism that is not native to an ecosystem that adversely affects it. these negative effects can include the extinction of native plants or animals, biodiversity destruction, and permanent habitat alteration. pine forests in british columbia have been devastated by a pine beetle infestation, which has expanded unhindered since 1998 at least in part due to the lack of severe winters since that time; a few days of extreme cold kill most mountain pine beetles and have kept outbreaks in the past naturally contained. the infestation, which (by november 2008) has killed about half of the province's lodgepole pines (33 million acres or 135,000 km2) is an order of magnitude larger than any previously recorded outbreak. one reason for unprecedented host tree mortality may be due to that the mountain pine beetles have higher reproductive success in lodgepole pine trees growing in areas where the trees have not experienced frequent beetle epidemics, which includes much of the current outbreak area. in 2007 the outbreak spread, via unusually strong winds, over the continental divide to alberta. an epidemic also started, be it at a lower rate, in 1999 in colorado, wyoming, and montana. the united states forest service predicts that between 2011 and 2013 virtually all 5 million acres (20,000 km2) of colorado's lodgepole pine trees over five inches (127 mm) in diameter will be lost. taiga climate change is having a disproportionate impact on boreal forests, which are warming at a faster rate than the global average. leading to drier conditions in the taiga, which leads to a whole host of subsequent issues. climate change has a direct impact on the productivity of the boreal forest, as well as health and regeneration. as a result of the rapidly changing climate, trees are migrating to higher latitudes and altitudes (northward), but some species may not be migrating fast enough to follow their climatic habitat. moreover, trees within the southern limit of their range may begin to show declines in growth. drier conditions are also leading to a shift from conifers to aspen in more fire and drought-prone areas. assisted migration assisted migration, the act of moving plants or animals to a different habitat, has been proposed as a solution to the above problem. for species that may not be able to disperse easily, have long generation times or have small populations, this form of adaptive management and human intervention may help them survive in this rapidly changing climate. the assisted migration of north american forests has been discussed and debated by the science community for decades. many of the species within historically survived changes in climate by migrating, and researchers have suggested that their natural migration will be too slow to outpace modern climate change. in the late 2000s and early 2010s, the canadian provinces of alberta and british columbia finally acted and modified their tree reseeding guidelines to account for the northward movement of forest's optimal ranges. british columbia even gave the green light for the relocation of a single species, the western larch, 1000 km northward. mountain pine beetle and forest fires adult mountain pine beetle climate change and the associated changing weather patterns occurring worldwide have a direct effect on biology, population ecology, and the population of eruptive insects, such as the mountain pine beetle (mpb). this is because temperature is a factor which determines insect development and population success. mountain pine beetle are a species native to western north america. prior to climatic and temperature changes, the mountain pine beetle predominately lived and attacked lodgepole and ponderosa pine trees at lower elevations, as the higher elevation rocky mountains and cascades were too cold for their survival. under normal seasonal freezing weather conditions in the lower elevations, the forest ecosystems that pine beetles inhabit are kept in a balance by factors such as tree defense mechanisms, beetle defense mechanisms, and freezing temperatures. it is a simple relationship between a host (the forest), an agent (the beetle) and the environment (the weather & temperature). however, as climate change causes mountain areas to become warmer and drier, pine beetles have more power to infest and destroy the forest ecosystems, such as the whitebark pine forests of the rockies. this is a forest so important to forest ecosystems that it is called the "rooftop of the rockies". climate change has led to a threatening pine beetle pandemic, causing them to spread far beyond their native habitat. this leads to ecosystem changes, forest fires, floods and hazards to human health. the whitebark pine ecosystem in these high elevations plays many essential roles, providing support to plant and animal life. they provide food for grizzly bears and squirrels, as well as shelter and breeding grounds for elk and deer; protects watersheds by sending water to parched foothills and plains; serves as a reservoir by dispensing supplies of water from melted snowpacks that are trapped beneath the shaded areas; and creates new soil which allows for growth of other trees and plant species. without these pines, animals do not have adequate food, water, or shelter, and the reproductive life cycle, as well as quality of life, is affected as a consequence. normally, the pine beetle cannot survive in these frigid temperatures and high elevation of the rocky mountains. however, warmer temperatures means that the pine beetle can now survive and attack these forests, as it no longer is cold enough to freeze and kill the beetle at such elevations. increased temperatures also allow the pine beetle to increase their life cycle by 100%: it only takes a single year instead of two for the pine beetle to develop. as the rockies have not adapted to deal with pine beetle infestations, they lack the defenses to fight the beetles. warmer weather patterns, drought, and beetle defense mechanisms together dries out sap in pine trees, which is the main mechanism of defense that trees have against the beetle, as it drowns the beetles and their eggs. this makes it easier for the beetle to infest and release chemicals into the tree, luring other beetles in an attempt to overcome the weakened defense system of the pine tree. as a consequence, the host (forest) becomes more vulnerable to the disease-causing agent (the beetle). the whitebark forests of the rockies are not the only forests that have been affected by the mountain pine beetle. due to temperature changes and wind patterns, the pine beetle has now spread through the continental divide of the rockies and has invaded the fragile boreal forests of alberta, known as the "lungs of the earth". these forests are imperative for producing oxygen through photosynthesis and removing carbon in the atmosphere. but as the forests become infested and die, carbon dioxide is released into the environment, and contributes even more to a warming climate. ecosystems and humans rely on the supply of oxygen in the environment, and threats to this boreal forest results in severe consequences to our planet and human health. in a forest ravaged by pine beetle, the dead logs and kindle which can easily be ignited by lightning. forest fires present dangers to the environment, human health and the economy. they are detrimental to air quality and vegetation, releasing toxic and carcinogenic compounds as they burn. due to human induced deforestation and climate change, along with the pine beetle pandemic, the strength of forest ecosystems decrease. the infestations and resulting diseases can indirectly, but seriously, effect human health. as droughts and temperature increases continue, so does the frequency of devastating forest fires, insect infestations, forest diebacks, acid rain, habitat loss, animal endangerment and threats to safe drinking water. mountain habitats mountains cover approximately 25 percent of earth's surface and provide a home to more than one-tenth of global human population. changes in global climate pose a number of potential risks to mountain habitats. researchers expect that over time, climate change will affect mountain and lowland ecosystems, the frequency and intensity of forest fires, the diversity of wildlife, and the distribution of fresh water. studies suggest a warmer climate would cause lower-elevation habitats to expand into the higher alpine zone. such a shift would encroach on rare alpine meadows and other high-altitude habitats. high-elevation plants and animals have limited space available for new habitat as they move higher on the mountains in order to adapt to long-term changes in regional climate. such uphill shifts of both ranges and abundances have been recorded for various groups of species across the world. changes in climate are melting glaciers and reducing the depth of the mountain snowpacks. any changes in their seasonal melting can have powerful impacts on areas that rely on freshwater runoff from mountains. rising temperature may cause snow to melt earlier and faster in the spring and shift the timing and distribution of runoff. these changes could affect the availability of freshwater for natural systems and human uses. marine ecosystems this section is an excerpt from effects of climate change on oceans. overview of climatic changes and their effects on the ocean. regional effects are displayed in italics. among the effects of climate change on oceans are an increase of ocean temperatures, more frequent marine heatwaves, ocean acidification, a rise in sea levels, sea ice decline, increased ocean stratification, reductions in oxygen levels, changes to ocean currents including a weakening of the atlantic meridional overturning circulation. all these changes have knock-on effects which disturb marine ecosystems. the primary factor causing these changes is climate change due to human-caused emissions of greenhouse gases, such as carbon dioxide and methane. this leads inevitably to ocean warming, because the ocean is taking up most of the additional heat in the climate system. the ocean absorbs some of the extra carbon dioxide in the atmosphere and this causes the ph value of the ocean to drop. it is estimated that the ocean absorbs about 25% of all human-caused co2 emissions. ocean temperature stratification increases as the ocean surface warms due to rising air temperatures.: 471 the decline in mixing of the ocean layers stabilises warm water near the surface while reducing cold, deep water circulation. the reduced up and down mixing reduces the ability of the ocean to absorb heat, directing a larger fraction of future warming toward the atmosphere and land. the amount of energy available for tropical cyclones and other storms is expected to increase, while nutrients for fish in the upper ocean layers are expected to decrease, as is the ocean's capacity to store carbon. at the same time, contrasts in salinity are increasing: salty areas are becoming saltier and fresher areas less salty. warmer water cannot contain the same amount of oxygen as cold water. as a result, oxygen from the oceans moves to the atmosphere. increased thermal stratification may result in a reduced supply of oxygen from surface waters to deeper waters, lowering the water's oxygen content further. the ocean has already lost oxygen throughout its water column, and oxygen minimum zones are expanding worldwide.: 471 these changes harm marine ecosystems, which can accelerate species extinctions or cause population explosions, altering species distribution. this also affects coastal fishing and tourism. rising water temperatures will also harm various oceanic ecosystems, such as coral reefs. the direct effect is coral bleaching on these reefs, which are sensitive to even minor temperature changes, so a small increase in temperature could have a significant impact in these environments. ocean acidification and temperature rise will also affect the productivity and distribution of species within the ocean, threatening fisheries and upsetting marine ecosystems. loss of sea ice habitats due to warming will severely impact the many polar species that rely on it. the interactions between many of these climate change factors increase pressures on the climate system and ocean ecosystems. monitoring studies on tropical coral reefs were made by bak and nieuwland (1995) in order to explore climate change on the sublittoral communities in