The correct answer would be - increase in green house effect, increase in temperature and rise in sea level are some major response.
Explanation:
Carbon dioxide concentration soar over 400 ppm which means there are 400 particles of carbon dioxide in a million particles of air. It is on the highest level of all time from the beginning. Carbon dioxide is a green house gas which means it is able to absorb heat and trap it in air which leads to increase in temperature of the earth.
Increase in earth temperature will lead to melting of ice lands which result in rise of sea level and cities will drown in sea. Other effect will be pollution in atmosphere and warmer climate and change in pattern of climate. There are many other direct and indirect response in accumulation of carbon dioxide concentration.
