What is climate change?
change includes many observed changes such as global temperature rise,
warming oceans, melting polar ice, glacial retreat, sea level rise,
increased extreme weather events and ocean acidification. These are the
result of on-going human activities, especially burning of fossil fuels,
which has added more than 1.5 trillion metric tons of carbon dioxide
to Earth’s atmosphere since the pre-industrial period, increasing its
concentration from below 300 parts per million (ppm) to over 415 ppm
today. One would have to go back millions of years in Earth’s history to
find such a high level of carbon dioxide. The last time carbon dioxide
levels were at similar levels was 3-5 million years ago before the
evolution of modern humans, when the world was 2-3°C warmer and the sea
level was 15-25 meters higher than today.
How fast is climate change happening?
past five years each ranked as the five hottest on record globally, as
did 19 of the past 20 years in this century. Global warming is fueling
destructive weather events, for example increasing wildfires and more
intense storms around the world. Greenland and Antarctica are losing
unprecedented amounts of ice and contributing to faster sea level rise.
Record high temperatures of the oceans are being recorded, which were
the hottest ever in 2019, and before that in 2018, and before that in
2017. Climate change is accelerating and leading to increasingly common
and destructive weather events, food and water insecurity, and
threatening human health.
What can we do to protect our future?
Immediate actions that are necessary to avoid the worst damages include suspension of fossil fuel uses and their rapid replacement with carbon neutral (or carbon negative) energy sources, prioritizing renewable solar and wind energy. Concurrently, careful management of carbon sequestration assets such as coastal marshes, forests and agricultural lands is also essential. The world’s nations committed to reducing greenhouse gases through the Paris Agreement in 2016 and it is imperative that these commitments be adhered to and enhanced in 2021 to avoid irreversible damages to Earth’s natural cycles and ecosystems and threaten human societies. Responses and actions are also needed at the national, regional, and local levels by institutional and individual leaders and citizens.