Question

The complete picture of the carbon cycle Fossil Fuel Burning Vegetation & Land Ocean 444 450 332| 338 Carbon cycle for the 1990s. Numbers are in billion tonnes of CO2 (IPCC AR4), This IPCC graphic shows CO2 flow between reservoirs in billions of tons. Using the data presented, explain how human activities can be cited as a major factor in climate change, if they are such a small percentage of overall CO2.

Answer 1

As it is seen in the image Vegetation and Land releases 444 billion tonnes of CO2 and it absorbs 450 billion tonnes of CO2. So, the net CO2 absorbed by the plants id 6 billion tonnes.

In the case of an ocean, it absorbs 338 billion tonnes of CO2 and it releases 332 billion tonnes of CO2. So, the net CO2 absorbed the oceans is 6 billion tonnes.

But in the case of fossil fuel burning 23 billion tonnes of CO2 is released in the atmosphere.

So, fossil fuel burning is the major contributor to the amount of CO2 in the atmosphere.

Fossil fuel include petroleum, diesel etc. which are used by humans.