Climate Change

In News: A study, conducted by researchers from University of Tasmania and University of Bonn discovered ancient sedimentary DNA (seda DNA).

• An international team studied fragments of deoxyribonucleic acid or DNA during the International Ocean Discovery Program, an international, multi-drilling platform research program., in the Scotia Sea, north of the Antarctic continent.
• This DNA is a million years old and makes it possible to study the responses of ocean ecosystems to climate change.

About:

• Seda DNA analysis is a new technique that helps decipher ‘who’ has lived in the ocean in the past and ‘when’.
• This comprises by far the oldest authenticated marine seda DNA to date.
• Marine seda DNA analyses can be expanded to hundreds of thousands of years, opening the pathway to the study of ecosystem-wide marine shifts and changes to paleo-productivity throughout many ice-age cycles.
• It can help study long-term responses of ocean ecosystems to climate change, as demonstrated by the study Ancient marine sediment DNA reveals diatom transition in Antarctica.

Significance:

• Antarctica is one of the most vulnerable polar regions and susceptible to climate change on Earth. West Antarctica is one of the fastest-warming regions globally. So, studying the frozen continent’s past and present responses to environmental and climate change is therefore critical and urgent.
• The study can help assess current and future changes in marine life around Antarctica.
• Understanding how Southern Ocean organisms respond to climate variability is necessary to predict how the Antarctic marine ecosystem will evolve in the near future.
• Global warming causes an increase in ocean productivity around Antarctica.
• Amongst the detected organisms were diatoms as key primary producers whose DNA was detected back to half a million years. Diatoms were consistently abundant during warm climatic periods. The last such change in the food web of the Scotia Sea occurred about 14,500 years ago.
• These periods of natural climate change can also give insight into the current and future human-induced climate warming and how the ecosystem might respond to it.

Source: Down to Earth

Previous Year Question

Q.1) The formation of ozone hole in the Antarctic region has been a cause, of concern. What could be the reason for the formation of this hole (2011)

1. Presence of prominent tropospheric turbulence; and inflow of chlorofluorocarbons
2. Presence of prominent polar front and stratospheric clouds; and inflow of chlorofluorocarbons
3. Absence of polar front and stratospheric clouds; and inflow of methane and chlorofluorocarbons.
4. Increased temperature at polar region due to global warming