Why is the Arctic warming faster than the rest of the world?

To explore this question, first we need to say what is the Arctic amplification effect? ??What impact does it have on the region and the world? Is Antarctica experiencing the same thing?

Human civilization and agriculture first appeared in the early Holocene (a geological century division) about 12,000 years ago. During this period, our ancestors benefited from a very stable climate, with atmospheric carbon dioxide levels remaining around 280 parts per million until the start of the Industrial Revolution in the 19th century.

Before the 19th century, the balance between energy (radiation) expenditure and income at the top of the atmosphere (the greenhouse effect) maintained average global temperatures for centuries. Only small changes in the sun's output and occasional volcanic eruptions cause relative warming and cooling. For example, the Little Ice Age was a cooler period between 1300 and 1870.

Today, carbon dioxide levels are approaching 420 parts per million, and carbon dioxide gas is increasing rapidly in all greenhouses due to the burning of fossil fuels, industrial processes, destruction of tropical forests, landfills and agricultural production. Since 1900, the global average temperature has increased by just over 1°C. This number may seem small, but the Arctic has warmed by about 2°C during this time, twice as much.

This difference in warming between the poles and the tropics is called polar amplification. It occurs when there is any change in the Earth's net radiation balance, which causes temperature changes near the poles to be greater than the global average. It is usually measured as the ratio of polar warming to tropical warming.

Melting Ice

How are climate changes and associated global warming driving Arctic amplification? This amplification is primarily caused by ice melt - Arctic ice melting The speed increases by 13% every decade.

Ice is more reflective and less able to absorb sunlight than land or ocean surfaces. When ice melts, it often exposes darker areas of land or ocean, which results in more sunlight absorption and associated warming.

The polar amplification effect is much stronger in the Arctic than in Antarctica. This difference is because the Arctic is an ocean covered in sea ice, while Antarctica is an elevated continent covered in permanent ice and snow.

In fact, the Antarctic continent has not warmed over the past 70 years, even as concentrations of greenhouse gases in the atmosphere continue to increase. The exception is the Antarctic Peninsula, which extends north into the Southern Ocean and has warmed faster than any other terrestrial environment in the Southern Hemisphere during the second half of the 20th century. Satellite data also shows that Antarctica lost an average of 149 billion metric tons of ice per year between 2002 and 2020, in part because the ocean around Antarctica is warming.

Effects of Arctic Warming

One of the most significant effects of Arctic amplification is the weakening of the west-east current in the Northern Hemisphere. Because the Arctic is warming faster than the tropics, this results in a weaker atmospheric pressure gradient, resulting in lower wind speeds.

The link between Arctic amplification, slow (or meandering) jet streams, blocking high pressure and extreme weather events in mid- and high-latitudes of the Northern Hemisphere is controversial. One view is that this link is strong and is the main driver behind recent summer heat waves and winter cold snaps. But recent research has questioned the validity of these links in mid-latitudes.

The Arctic is warming much faster than the rest of the planet, and 30 to 50 percent of the planet's global warming is caused by the loss of reflective ice. This rapid loss of ice affects the polar jet stream, the collecting path of air in the upper atmosphere that drives weather patterns in the Northern Hemisphere. The weakening jet stream bends and pushes the polar vortex further south, causing extreme weather events in North America, Europe and Asia.

So what are the climate future prospects for Australia and Australia/New Zealand? Global climate models show that the Arctic is experiencing more surface warming than the Antarctic under the influence of climate change. Despite increases in greenhouse gases, the Antarctic continent has remained stable for more than 70 years. However, as the tropics continue to warm and expand, we can expect the pressure gradient between the tropics and Antarctica to increase, which will result in increased circumpolar westerly winds.

The recent intensification and poleward position of the westerly winds in the Southern Hemisphere has been linked to continental droughts and wildfires, including those in Australia.

We can also expect that increasing westerly winds will affect the Southern Ocean convergence, which may reduce the Southern Ocean's ability to absorb carbon dioxide and increase the melting of ice shelves at the edge of the West Antarctic Ice Sheet driven by ocean loading. These changes, in turn, have profound effects on global ocean circulation and sea level rise.