Warming Planet, Dissapearing Glaciers

Summary

This lecture discusses the impact of climate change on glaciers, emphasizing their rapid retreat worldwide. It highlights examples from Mount Kilimanjaro, Montana Glacier National Park, and Saskatchewan Glacier, showing clear evidence of shrinking ice masses. The lecture also explores the accelerated melting in the Arctic, Greenland, and Antarctica, which has significant consequences beyond aesthetics, including threats to biodiversity and rising sea levels. The rapid melting of glaciers in the Himalayas is particularly alarming, as it affects the freshwater supply for millions of people, posing long-term risks to agriculture and drinking water availability.

Takeaways

• 🌍 Glaciers are shrinking due to global warming, leading to a significant reduction in their size worldwide.
• 🏔️ Mount Kilimanjaro's glacier has retreated by over 80% in the last 100 years.
• 🇺🇸 Montana Glacier National Park had 150 glaciers in 1910; now, only 30 remain.
• 📅 The Grinnell Glacier in Montana has visibly shrunk over the decades, as seen in photos from 1938, 1998, and 2009.
• 🇨🇦 Saskatchewan Glacier in Canada also shows significant recession from 1924 to 2011.
• 🧊 The Arctic is experiencing a reduction in ice year-round, with nearly half of the ice pack disappearing by volume since 1970.
• 📉 The record for the lowest sea ice extent in the Arctic was set in 2012, signaling alarming trends.
• 🌍 Greenland's ice sheet is melting at an accelerating rate, with the melt zone moving northward.
• ❄️ Antarctica's warming rate is faster than anticipated, with western Antarctica warming significantly more than other areas.
• 🌊 Loss of glaciers poses significant risks, including rising sea levels, reduced biodiversity, and loss of fresh water for millions of people.

Q & A

What is the main focus of the lecture in part four?

The main focus of the lecture is the impacts of climate change on glaciers, specifically the shrinking of glaciers due to global warming.

How much has the glacier on Mount Kilimanjaro retreated in the last 100 years?

The glacier on Mount Kilimanjaro has retreated by more than 80 percent in the last 100 years.

How many glaciers were there in Montana Glacier National Park in 1910, and how many remain today?

There were 150 glaciers in Montana Glacier National Park in 1910, but today there are only 30 glaciers left.

What is the trend seen in the images of Grinnell Glacier in Montana?

The images of Grinnell Glacier show a clear pattern of recession, with a noticeable reduction in glacier size from 1938 to 2009.

What is the difference between sea ice and glacier ice in the Arctic?

Sea ice in the Arctic is made from seawater and floats on the ocean's surface, while glacier ice is made from fresh water and is found on land.

How much of the Arctic ice pack by volume has disappeared since 1970?

Nearly half of the Arctic ice pack by volume has disappeared since 1970.

What is happening to the Greenland ice sheet in recent years?

The Greenland ice sheet is experiencing an accelerating rate of melt, with the melt zone moving northward in elevation.

What has been the temperature increase at Byrd Station in Western Antarctica over the past 50 years?

The average annual temperature at Byrd Station in Western Antarctica has increased by 4.3 degrees Fahrenheit in the last 50 years.

Why is the loss of glaciers not just an aesthetic issue?

The loss of glaciers has significant implications for biodiversity, wildlife, and rising sea levels. It also affects the availability of fresh water for millions of people.

How do glaciers in the Himalayan region impact the surrounding population?

Glaciers in the Himalayan region feed rivers such as the Ganges, providing fresh water for drinking, agriculture, and hydroelectric power. The rapid melting of these glaciers threatens water availability for millions of people.