Part 2. Recent Climate Extremes

Now that we have explored some past cold extremes and impacts in northwestern North America, we will turn our focus to recent and future climate warming and regional impacts in the Arctic. As you might know, recent increases in global temperatures and climate extremes are linked with greenhouse gases in the atmosphere, such as carbon dioxide and methane, that have been increasing at a rapid rate due to human activities. Take a moment to watch a brief video explanation of the causes and consequences of global warming. Human-caused (or 'anthropogenic') climate change is a hot topic, and there are many concerns and uncertainties about what climate will look like in the future, and the impacts that it will have on human populations and our environment. How can we assess recent climate changes, learn about its impacts on people and ecosystems, and predict future changes?

While we learned about the importance of paleoclimate data (like tree rings), to put recent climate changes in a long-term context, the broad availability of instrumentalweather/climate data collected from instruments at a weather station, for example and satellitean instrument placedin an orbit around Earth that collects information (e.g., imagery) of the Earth's surface data are invaluable for attaining a good understanding of the recent changes that are occurring around our planet. For example, instrumental measurements from thousands of weather stations on land, ships, and buoys are used to assess changes in global mean temperatures, such as shown below from the Surface Temperature Analysis (v4) from the NASA (the National Aeronautics and Space Administration, a U.S. government agency) Goddard Institute for Space Studies (GISS). Here, the instrumental data are also shown as anomalieschanges in climate relative to a baseline (example, the average) , or changes in temperatures relative to average temperatures from 1951-1980. The temperature data spans the instrumental period of 1880-present (2023).When do the most extreme high temperatures occur over the instrumental period? What do you notice about the year 2023?

Figure 6: Global temperature anomalies from the year 1880 to 2023 from the Surface Temperature Analysis (v4) from NASA GISS.

Through analyzing large datasets derived from instrumentalweather/climate data collected from instruments at a weather station, for example and satellitean instrument placed in an orbit around Earth that collects information (e.g., imagery) of the Earth's surface records, we can also investigate the spatial characteristics of recent temperature extremes, as well as other environmental changes. For example, take a look at the Climate Time Machine website from NASA and explore some of the different 'topics'. Be aware that the website can take some time to load. There are several visualizations of changing climate around the globe, all of which illustrate climate extremes that have occurred in recent years. Click on the 'Global Temperature' topic on the Climate Time Machine and play the animation, which spans the years 1884-2022, and pay particular attention to warm temperature extremes in recent decades around northwestern North America.

In addition to temperatures, data-gathering instruments all around the globe collect information about many different environmental variables, such as precipitation, wind speed, and humidity, to name a few. In more recent decades, Earth scientists have also used satellite data to assess global environmental changes in ways that were previously not possible. Satellite data can be used to track sea level, changes in ice extent, atmospheric chemistry, and land cover, among many other environmental variables. These data can complement information we obtain from tree-ring records to better understand the spatial characteristics and timing of recent climate extremes. For example, click on the 'Sea Ice' topic of the Climate Time Machine, and read the text and watch the animation. A reduction of Arctic sea ice since the beginning of the satellite record (1979) is apparent through time, including off of Northwestern North America.

In this section, we will explore recent environmental extremes in northwestern North America, and learn about how critical changes in climate have impacted Indigenous communities in Alaska.

Recent Extremes and Impacts in Indigenous Communities of Alaska

In recent decades, scientists have been closely tracking regional climate change, extreme weather events, and associated impacts and risks. This has especially been the case in Alaska and other regions of the Arctic, where climate change has been strongly felt. The US Global Change Research Program (USGCRP) produced the Fifth U.S. National Climate Assessment in November of 2023, which is a report detailing climate changes and its impacts in the United States. There is a chapter specifically on Alaska. Take a close look at the following infographics from this report, which illustrate a) some of the climate extremes that have occurred in recent years, and b) related ecological changes.

Figure 7: Climate extremes, events, and related ecological changes in Alaska from the Fifth US National Climate Assessment.

Arctic Indigenousthe original Peoples of a region, and their descendants, that share distinct cultural traits Peoples, who are experiencing changing environmental conditions first hand, have considerable knowledge on regional climate extremes and ecological impacts. Their voices and experiences provide a powerful dimension to our understanding of climate change, in part due to their intimate connection and relationship with their homeland and nature. Indigenous knowledge has been passed down through generations, and their stories shed light on the magnitude of recent and historical climate extremes, and impacts and threats on livelihoods and local practices. First, to learn about the importance of Indigenous knowledge in many realms of science, including climate change, take a look at this PBS video. And then shifting to the Arctic region of Alaska specifically, take a look at the 15-minute documentary "A Culture on the Edge of the Ice", which includes interviews to document climate change and its impacts on the Siberian Yupik Village of Savoonga (a remote island in the Bering Sea). If you are watching this video in the classroom, you could watch the video together with all other students, or you could watch independently with headphones.

Indigenous perspectives will be essential in efforts of adapting to, and solving, challenges associated with climate change. Optional: if you are curious to learn more, be sure to watch this TED talk from Jade Begay, an Indigenous rights expert, who describes the importance of understanding climate change impacts on Native communities, the role of Indigenous knowledge for climate change adaptation and solutions, and building partnerships.