Mass Extinction can be defined as a time period in which large species go extinct i.e. no more reproduction.
Please note that each extinction period has millions of years.
Previous 5 mass extinction had already occur on the earth. I will briefly enumerate here:
First, upto 85% all living species eliminated on earth. Reason was continental drift i.e. earths has major plates in geographical terms and that plates were drifting towards each other. (Note: Reason was Natural)
Second, Nearly 80% of all living species eliminated. Reason was Lack of Oxygen and Volcanic eruption. (Note: Reason was Natural)
Third, also known as 'Great Dying', Nearly 96% of all living species eliminated. Reason was Asteroid Stokes, Volcanic Activity.(Note: Reason was Natural)
Fourth, More than half of all living species eliminated. Dinosaur's extinction is the best example in this period. Reason, changing pH value and sea level of oceans.(Note: Reason was Natural)
Fifth, also known as K-T mass extinction, nearly 75% plus remaining Dinosare's were extincted in this period. Reason, Extreme Asteroid or Meteor Impact (We can see asteroid falling on the earth at night and creating light but it is very small asteroid to have any impact or it burns totally before reaching on earth surface). (Note: Reason was Natural)
Now, Ongoing 6th Mass Extinction:-->
This ongoing 6th mass extinction is one of the most environmental threats to the civilization!!!(Yes it is true, any Environmental Scientist will told you how catastrophic effect of climate change is on Human Civilization).
It is estimated that around 510 kingdom species (like our ancestor Chimpanzee) are in the threat of EXTINCTION. Out of 510, South America(30%), Oceania i.e land surrounded by water (Number of Island) (21%), Asia (21%), and Africa (21%) are in the most red zone.
Reason is : Natural + Artificial (More of Human Cause). Humans population have increase faster as compare to other species. This required more resources for human survival like Energy, Food, Shelter etc. This is accepted as a basic needs. But as human need evolving day by day, more resources are being depleted from earth and at the same time exerting polluting items like CO2, Methane, HFCL etc. Note: All this arises from our comfort life. Example: Fuel, Gases from devices like Refrigerator, Air Conditioner, Vehicles, Fog etc.
All this thing causing catastrophic effect on climate change. So, UNFCC (United Nations Framework for Convention on Climate Change) created global consesus regarding Carbon Offset in 2016, also known as Paris Agrrement (More information at: https://unfccc.int/process-and-meetings/the-paris-agreement/the-paris-agreement). According to this agreement, Global Warming temperature should be reduce by 1.5 degree Celsius/ 2.7 degree Farahnide. This can save millions of species on earth from endangered/extinction.
So, UNFCC has already declared the road-map for achieving this target in 20 points programmed (Some/many of us would surprise that 1.5 C/2.7 F is just small number but that is not the case. They can find more information at: https://www.nationalgeographic.org/encyclopedia/global-warming).
What we can do?
My personal opinion:-
At least recognize that climate change and Global warming is threat to our own survival/existence. (Don't follow those persons who says Climate Change is a Hoax).
Reduce waste water. Importance of one drop of water is better realize by those living in dessert/water scarcity zone.
Imagined, if today every individual plant a tree in memory of her/his life, how will earth look in the next 20 years. So, Plant a tree for the Mother Earth. Don't forget she gave you a precious life which is not possible on other planet.
Consumed to the proportion of your daily needs. Example: Water, Light, Daily Necessities etc.
Use Renewable Energy resources. Example: Biogas, Wind Power, Solar Power etc.
If you want buy appliances, invest them in energy-efficient appliances. That saves your electricity bills and environment too.
If you are farmer, Do organic Farming. Now days organic products are in huge demand. That will be cash incentive and less environmental impact.
Buy LED lights at home. It saves lots of energy.
Eat less meat or Eat more organic/natural foods.
Drive Fuel-Efficient vehicle. Example- Hybrid and Fully Electric vehicles.
Shrink your carbon profile. Yes it is true, as every individual is adding Carbon to the environment. You can offset your carbon by purchasing carbon offset if possible.
Yes, I will do my best to raise awareness..Thanks.