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Climate Change FAQ
What is the difference between climate and weather?
Climate refers to long-term, average weather patterns in a geographic area. Climate conditions (“normals”) are calculated for longer time intervals, such as average weather conditions over 30 years. Weather is what you see outside your window today, or the pattern you notice over shorter time spans (for example, a “rainy week”). Scientists predict that extreme weather events will become more frequent and intense because of changes in the climate.
What is climate change?
Climate change is a long-term change in a region's climate. This includes the entire Earth changing from what is considered normal. These changes can include temperature, wind patterns, or precipitation (rain and snow) levels. Climate change takes place naturally over time because of many different factors, like the distance from the Earth to the Sun, the intensity of sunlight, and the amount of particulate matter in the air reflecting sunlight back into space. Today, scientists agree that natural processes can be sped-up by human activities, like burning fossil fuels and land-use activities. This causes a higher rate of change compared to what happens naturally.
What drives climate change?
Greenhouse gases (GHGs, or "heat-trapping" gases) trap heat radiation in the atmosphere. The four main GHGs are water vapour, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). These gases absorb heat reflected by the Earth instead of releasing that heat to space. The greenhouse effect makes Earth habitable by keeping temperatures at a suitable level for life as we know it. Human activities, such driving a car, burns fossil fuels and emits GHGs. GHGs in the atmosphere have increased since the industrial revolution (1750). Current levels of known greenhouse gases, like methane and carbon dioxide, in the atmosphere are also the highest they have been in more than 650,000 years. GHGs are referred to as drivers of climate change because their presence in the atmosphere alters the Earth’s energy balance by trapping heat in the atmosphere. Land-use practices such as agriculture also emit GHGs and are another example of a climate change driver.
What is global warming?
Global warming refers to a rise in the average global surface temperature over time. The opposite is global cooling, a decline of the average global surface temperature. Global warming doesn’t mean the planet’s temperature rises all at once. Some areas will be hotter, while others may get colder; however, there is an overall warming trend. Global warming is an example of a change in global climate. Atmospheric temperature data that has been collected for the last 120 years indicates the Earth is warming. The temperature data has been compared with data from other indicators including tree rings, ice cores, ocean coral and ground temperatures. Together, this data allows us to see what temperatures were like in the past. It indicates 2000-2010 was the warmest decade in modern times. The Arctic has warmed at a higher rate than the annual global average temperature.
How will climate change impact Nunavut?
In the Arctic we are already observing changes in our environment, including:
- Declining thickness and extent of sea, river and lake ice
- Warmer temperatures
- Changes in vegetation and wildlife: new species are being observed (moving further north), and well-known species are being observed in new areas
- Changes in the permafrost regime and hydrology of the tundra
- Increased frequency and intensity of extreme weather events
- Rising sea levels in certain places
- Melting and shrinking glaciers
What are elders reporting?
Elders are reporting the same changes as scientists (see question above):
- Sea ice conditions have changed; the ice is thinner, freezes up later and melts earlier. Similar observations have been made for lake ice.
- Aniuvat (permanent snow patches) are decreasing in size. There is more rain, and snow and ice forms later in the year and melts earlier (the quantity and timing of precipitation is changing).
- The weather is unpredictable and doesn’t follow the patterns it did in the elders' youth. The weather changes faster than it used to, with storms blowing up unexpectedly.
- Water levels have gone down, making it hard or impossible to travel by boat in certain areas (partly due to isostatic rebound; see below for explanation).
- Temperatures are warmer throughout the year.
- New species of insects, birds, and animals have been observed.
- The land has been noticed to be drier and the stability of the permafrost is changing.
- The length and timing of seasons have changed.
How can climate change affect permafrost?
Permafrost is frozen soil or rock that has been frozen for at least 2 years in a row. Permafrost degradation refers to thawing permafrost, which is frozen soil that is thawing or getting warmer. With the temperature increasing, the amount and depth of permafrost can decline. Certain areas of permafrost contain more ice than others. When the ice in the soil (for example, ice wedges) melts, the soil becomes wet and may slump down. Frozen soil is hard – when it thaws it turns soft. Infrastructure in Nunavut relies on the permafrost for stability. When the permafrost degrades, the load-bearing capacity of the permafrost decreases and the soil can become unstable (buckling, sinking, etc.) and cause damage to houses, roads, airports and other facilities.
What is the active layer?
The active layer is the top layer of the soil (or surface materials), which thaws in the summer and freezes up again in the fall. The depth of the active layer varies across Nunavut, and even within communities. It depends on factors such as soil type and location (for example, proximity to a river).
What is subsidence?
Subsidence describes permafrost soil that was held up by ice collapses as the ice melts. This can be seen as irregular surfaces – for example, hummock tundra. The small hollows created by subsidence can be filled in with water. Subsidence can create issues in areas with built infrastructure (e.g. roads, buildings, airports), and it can lead to the development of sinkholes.
Isostatic rebound happens when land that was pressed down in the last ice age by the glaciers rises as a result of disappearing ice. The depressed land is "bouncing back", or rebounding – a process called isostasy. In some places in Nunavut, the land is rebounding faster than the sea level is rising. This makes it appear as if the sea level is actually dropping, although on a global scale scientists have confirmed sea levels are rising.
I’ve heard stories about the ice in the Arctic. What’s going on?
Since the 1970’s, scientists have been monitoring Arctic sea ice using satellites. Using this data they have determined the amount of sea ice is declining year after year. Arctic sea ice has been in decline since at least the 1950’s. Scientists predict the Arctic could see its first ice-free summer as early as 2030. What does a reduction in sea ice cover and depth mean for Nunavummiut? A decrease in sea ice impacts travel between communities during the spring and fall, as there will be a shorter period of time that the ice will be suitable for travel. Not only that, it means that traditional hunting practices may no longer be safe and viable. It also opens up previously inaccessible areas for exploration, tourism and shipping, which can lead to increased economic opportunities for Nunavut. On the other hand, it will translate into increased risks to the environment, most notably through spills and other pollution incidents. This will require improved research, monitoring and emergency response capabilities.
Will our Arctic animals be affected by climate change?
Climate change is affecting Arctic vegetation and wildlife through a variety of impacts. Changes in range distribution, habitats, abundance, genetic diversity, and behavior of migratory and non-migratory species have already been observed. Overall, the number of species in Nunavut is projected to increase as southern species potentially move northward with a changing climate. Current Arctic species will see changes in their habitat including new plants, reduced ice cover, changing snow patterns, changing ocean salinity and increased acidity. This can potentially affect species numbers and distribution.
For example, polar bears are highly intelligent and adapt quickly to changing conditions. They have lived through many climate change cycles in the past, so they can likely manage changes that might happen. However, it is possible there will be changes in their range distribution and composition. Some areas may experience reduced polar bear numbers. In other areas, polar bears may cease to exist during the warmest period. Other regions may experience higher numbers of polar bears as a changing climate improves polar bear habitat by reducing multi-year ice. Elsewhere, polar bear numbers and polar bear productivity may remain steady.
What is a storm surge?
Storm surge refers to a temporary rise in the height of the sea along a coastline. This kind of large wave moves with, and is caused by, strong storms with spiralling winds
What is climate change adaptation?
Climate change adaptation refers to any action that combats the negative impacts of climate change or takes advantage of potential new opportunities. Adaptation can be spontaneous, planned or proactive.
What is meant by the term “adaptive capacity”?
Adaptive capacity is a region or community’s ability to manage the impacts and risks of climate change.
What is climate change mitigation?
Mitigation is about reducing the amount of Greenhouse gases (GHGs) emitted to the atmosphere. It is different from adaptation, which is a response to the changes created by the emission of those Greenhouse gases.
What is vulnerability?
Vulnerability refers to the degree to which a natural or anthropogenic (human-made) system is susceptible to, or unable to deal with, the impacts of change.
How can we prepare in the face of a changing climate? What can I do?
Although Nunavummiut emit a small amount of GHGs in total, we are among the highest emitters of GHGs per person in Canada and the world. Although mitigating climate change by reducing the amount of GHGs we emit is very important (and this can be done by making energy-wise decisions), current scientific predictions suggest that even if we stopped all GHG emissions today, global average temperatures would continue to rise due to lags in the climate system. In other words, we will have to adapt to current and anticipated changes in our environment.
The Government of Nunavut has worked in partnership with communities, the Canadian Institute of Planners (CIP), Aboriginal Affairs and Northern Development (AANDC), and Natural Resources Canada (NRCan) to develop pilot community climate change adaptation action plans and methodologies to determine impacts of changing permafrost conditions and a rising sea level on Nunavut communities. By working together as partners and incorporating known impacts of climate change into our decision-making and planning at all levels, we will be prepared to face a changing climate.