Hi! So you want to know, why your favorite polar bears are dying.
No, I won’t be talking about climate change.
Alright! So, shall we start with a question?!
What comes to your mind when you think of polar bears?
A cold freezing place! Maybe Arctic
Yes, this place where polar bears stay is known as Arctic. Not only polar bear, it’s also home to Arctic foxes, walruses, seals, narwhal and whales.
The Arctic is the northernmost part of our planet which consists of the Arctic Ocean and parts of Canada, Russia, the USA, Greenland, Norway, Finland, Sweden and Iceland.
Here, the temperature even goes as low as -40oC. You see, how much the polar bears have adapted themselves to stay in this freezing temperature! The ICE!
Now what if I say that the temperature they reside in won’t stay long!
You read it right.
The ice is melting because of something called ‘Arctic Haze’ caused by us. This melting of ice leads to limited access of seals to polar bears. Here, seals are source of food for the polar bears. Hence, lesser the seals, lesser will be the polar bears!
Now don’t think I am being partial towards the polar bears. Check why they matter section to know more. And I am sure you will be assured that getting polar bears right will fix everything including the wildlife and the indigenous ‘Induit’ people’s life.
Now, let’s get to the cause of polar bear’s death.
Yes! We are causing Arctic Haze due to which the ice is melting and hence polar bears are dying.
By looking at the picture, does it sound familiar to you? The haze in metro cities like Mumbai, Delhi, Bengaluru! Due to vehicular pollution maybe!
Now you know that Arctic Haze is also caused by anthropogenic activities, which results in global warming and in turn increased melting of ice. The Arctic haze is different from the haze I talked about earlier, in terms of composition of pollutants and the ability to persist in nature for a longer period of time.
According to Shaw, the Arctic Haze is caused due to high concentration of air pollutants during winter period. Specifically the winter period because there is no precipitation, snow, turbulent air to wash out the pollution. Thus the effects are strongest because pollutants can warm the environment.
Do you remember the color of haze we talked about in metro cities? That is grayish which is due to dust, auto exhaust, and industrial manufacturing, etc.
The color of Haze depends on the pollutants composition!
Let’s see for Arctic Haze-
The Arctic Haze consists upto 90% sulphates and rest as black carbon (soot), due to which it gets its reddish brown color. These 2 components are major drivers for global warming and are result of anthropogenic activities.
It also additionally contains hydrocarbons (particulate organic matter), dust aerosols, ammonium and nitrate. These aerosols are also called particulate matter (PM2.5 orPM10) or nanoparticles.
The aerosols- fine solid particles or liquid droplets suspended in the atmosphere- play a major role in global warming. They can be either directly associated with scattering/absorbing the light or indirectly associated with helping in cloud formation, thereby changing its properties.
When areas of high and low pressure, force winds from south region up into the Arctic, the aerosols are carried as far as the North Pole.
So the nature of aerosols in Arctic Haze is follows:
Nature of aerosols
However the net effect is cooling in Arctic summer. But warming in Arctic Winter!
So what is different about Winter?! Let’s see-
By the way do not skip by looking at the TERMS. I assure you I will get you through it by flying colors!
Normally, temperature decreases with increase in altitude (height). But in Arctic winter, it is opposite.
The warm air consisting of aerosols (sulphur, carbon, etc) when comes in contact with Arctic cold air, the warm air being less dense moves over Arctic’s cold, dense air. This means there is increase in temperature with increase in altitude and thus ‘Temperature Inversion’.
If you did not get this, don’t worry. Refer the below given Infographic!
Cold air = Low temperature
Warm air = High temperature
Temperature Inversion in Arctic Winter
This process blocks the atmospheric air flow, making the system more stable. And thus the Arctic Haze will more likely loom over the Arctic for the next winter months.
Also in Arctic winter, remember there is no sunlight; it is a dark, cold, stable place! This brings me to another point…
Normally, when sunlight falls on earth’s surface, shortwave radiation (high energy) is received by the earth. This surface then emits longwave infrared radiation (low energy) to the outer space, resulting in cooling of atmosphere. This phenomenon is called enhanced ‘Infrared Radiative Cooling’.
But in Arctic there is no sunlight, it is a dark place, remember!
This means NO REFLECTION.
Thus the outer warmer air consisting of carbon and sulphur aerosols won’t reflect and cool, rather they would re-emit to the surface causing Global Warming.
Another reason for warming…
So in Arctic winter surface emits longwave infrared radiation, but this warm air comprising of aerosols acts as a barrier and thus receives the radiation, leaving no space for radiation to escape. In this case the warm air tends to re-emit downwards back to the surface in order to keep itself cool causing Global Warming.
Also warmer the object, more the infrared radiation!
More the Infrared radiation, more the warming!
This means, warmer the surface, more the trapped infrared radiation, MORE THE WARMING.
This is the same phenomena that takes place in presence of ‘Greenhouse gases’ as well.
The warming can also increase due to deposition of soot (black carbon) on the snow. This deposition of soot leads to more absorption of sunlight resulting in melting of ice. And hence ‘Global Warming’ takes place.
The clouds also work the same way, thus enhancing Global Warming!
And we are done! Did you get the Formation part? Comment down below and do let me know!
If you want to know more, the best paper I can suggest is THIS! I guarantee you will fall in love with Arctic science after reading this.
1) Coal-burning: Aerosols containing sulphur and carbon
Origin – northern mid-latitudes
This pollution is helping the Arctic warm up faster than any other region.
2) Sulfates: Power plants, pulp and paper mills and oil and gas activities. Industries such as vehicles, shipping and agriculture.
Origin – Heavily populated and industrialized areas of Europe, North America and Asia.
3) Natural aerosols: Dust, and volcanic aerosols such as sulfur oxides.
Origin – Deserts, volcanic eruption
4) Anthropogenic aerosols: Particulate matter (PM) such as soot and coal ash, forms of dust, smoke, and more.
If you are thinking that there are no as such industries in Arctic which might be causing pollution you are right! But we also talked how emissions from 1000’s of miles travels and reaches the Arctic. So every carbon footprint of yours counts!
If you are thinking, India’s pollution is not reaching Arctic. Then you are wrong!
According to Tim Garrett, the haze appeared to be grayish which came from India as a result of industrial pollution, home fires, etc and to give you an idea how far India is from Arctic that it is causing pollution there. I have this screenshot for you.
Can you spot India and Arctic?
Source: Google Earth
If warming continues unabated, then Arctic’s summer sea ice may completely disappear by 2040.
You see the danger looming over Polar bears, associated with them the wildlife, the Inuits?!
Do your bit!
To know how you can save polar bears you can reach out to SAVE US!
ALSO, COLD WON’T KILL OFF THE POLAR BEARS, BUT GLOBAL WARMING CAN. AS POLAR ICE DISAPPEARS, SO DOES THE HUNTING GROUND FOR SEALS.
P.S.: I am glad my research about saving polar bears in Arctic brought you here!