A Frigid Fate

Polar Bears in a Warming World

Things are heating up in the arctic...

A Closer Look into Climate Change

Arctic sea ice has overall decreased over the years, due to global warming, which has resulted from detriments such as increased carbon dioxide emissions.

But what do rising temperatures and decreasing ice mass mean for polar bears?

Let's take a closer look at the 19 subpopulations of polar bears in the Arctic

*Data from 2021.

How did the melting of the Arctic sea ice affect polar bears in each of the 19 subregions?

The majority of subregions experienced sea ice loss. Chukchi Sea lost the second largest sea ice extent with 25%, which is alarming because this region also has the largest polar bear population. Its neighbor, the Southern Beaufort Sea, also lost a moderate amount of ice, and its polar bear population has been declining since 2006. The combination of high sea ice loss and declining polar bear population in these two areas makes them points of interest.

Let's zoom in on these two subregions in a bit more detail.

The data comes from The IUCN Polar Bear Specialist Group report and Statista.

Migration Towards Land

*We truncated the dataset, retaining data points for every five-year interval for efficiency and loadtime.

Over the last 30-40 years, polar bears in the Chukchi and Southern Beaufort Sea regions have been migrating further and further south, away from the center of the arctic ice circle and towards land (Alaska, Canada) due to the decreasing ice extent.

Here we have an aerial view of the top of the arctic circle, with dots representing the locations of polar bears in the Chukchi and Southern Beaufort Sea regions.

How do we know this?

Scientists have been tracking polar bears by placing radio collars on them. The collars emit signals that can be picked up by satellites, which allow scientists to track the polar bears' movements.

Polar Bear Diet Trends

Naturally, polar bears are adapted to live on sea ice, and they rely on sea ice to hunt seals, their main food source. As sea ice melts, polar bears must adapt to changes in their environment. Population trends from 2021 show that Southern Beaufort Sea polar bear populations have likely decreased. Specifically, let's see how the diets of Southern Beaufort Sea polar bears have changed between 2004-2016.

Southern Beaufort Sea polar bears have consumed less Beluga whales throughout the years. This difference in polar bear diet throughout the years indicates their changing environment and the potential impact of climate change on other arctic species like whales.

We accessed the dataset from USGS Alaska Science Center - Polar Bear Research Program. To obtain the percentage breakdown by diet type in a particular year, we calculated the total consumption of each food source from that year and divided by the number of polar bears captured. This yields the average consumption (as % of total diet) of each food source.

Explore the health of the Southern Beaufort polar bear population below!

How to Explore:

Click on the View a Polar Bear button to see an individual polar bear's health data and compare it against the dataset.
Brush one or mulitple axes to view polar bears who fall into the intersection of all of the brushed regions.
Filter the data displayed by sex or ageclass.

*Data filtered to polar bears with non-NA values for the 9 criteria above.

In the End, It's About More Than the Bears

Our planet's majestic polar bears are facing unprecedented challenges due to the rapidly changing climate. As their icy habitats melt away, we must be more conscious of our actions and their impact on the environment. However, climate change affects more than just the arctic. Climate change is a global crisis that transcends polar boundaries. From rising sea levels and extreme weather events to disruptions in ecosystems and loss of biodiversity, the consequences are far-reaching.

Spread awareness and take action to safeguard our planet and the incredible species that depend on it for their survival.

Thank you!

Huiwen Chen '25

CS @ Harvard

Jessica Li '25

Stat & CS @ Harvard

Kathy Zhong '25

CS @ Harvard