Radio programme - AWAZ Radio (Wednesday 15 July 2020)
Q1: What is the difference between weather and climate?
Weather refers to atmospheric
conditions (temperature, pressure, wind speed, rain etc.) at a particular time
and location.
Atmospheric conditions, and hence the weather, can change very quickly.
Climate is average atmospheric conditions
over a period of time – normally 30 years or more.
Climate does not change much from one year to the next.
Q2: Is global warming (GW) the same as climate change (CC)?
GW refers to warming that is caused by
humans – a recent phenomenon – mostly since the start of the Industrial
Revolution over 200 years ago.
CC can be both human caused or can occur
naturally (but on a much longer time scale of several thousands of years)
"Today’s global warming
is an unprecedented type of climate change, and it is driving a large
number of side effects (e.g. melting of polar ice sheets, warmer oceans)"
"It’s
these side effects that are likely to have a much greater impact on society
than temperature change alone."
Q3: Many
people claim that Climate Change (CC) is one of the most serious threats to
human civilization.
Why should we be concerned about CC?
Could you describe some of the undesirable effects of CC.
CC will impact all aspects of our lives:
1. Changes in sea-level will affect cities
along heavily populated coastlines causing disruption for 100s of millions of
people by 2050.
2. Worldwide retreat of mountain glaciers
– millions of people depend on for drinking water & agriculture
3. Extreme weather events – extensive wildfires,
more severe hurricanes, droughts, excessive and intense rainfalls causing flash
floods etc.
4. Tropical diseases - move to regions of
higher latitudes. People have less immunity in these regions
5. Air pollution – due to high particulate
emissions – already responsible for several
million people dying prematurely every year
6. Habitat Loss – due to clearing of
forests – serious reduction in biodiversity
7. Migration – Hundreds of millions of
people will migrate from un-inhabitable tropics (too hot to live, droughts) to
northern regions.
8. Food scarcity – It will be too hot to
grow crops efficiently – may not be sufficient food to feed the 11 billion
population expected by 2100.
9. Ocean
Acidity – Oceans will become more acidic affecting survival of coral and
other sea creatures.
10. Oxygen depleted Ocean Zones – Vast areas of the oceans will be unable to support life due to lack of available oxygen in the water
Q4: What should we do to control CC? Is it expensive?
The main cause of CC is burning of fossil
fuels (FF). We need to urgently reduce
our dependence on FF.
This involves changing our wasteful
habits, adopting life-styles and habits that require less energy consumption
(e.g. energy conservation, less air-travel, eating more vegetarian meals etc.)
Estimates are that nations need to spend ~1% of GDP to tackle CC (£25 billion per year in UK; £150 billion per year in USA)
Q5: Who will be most adversely affected by CC?
Everybody will be affected by CC.
Poor countries will be most seriously
impacted. They tend to have large populations and will find it difficult to cope with CC. Most regions in the tropics might become un-inhabitable creating a huge refugee problem (may be a 1 billion or more migrants) for the rest of the world.
Also poor communities in rich nations will be severly effected by CC.
Q6: Why can’t the world governments come together to solve the problem?
Governments operate with short time horizons of a few years at most. Additionally, there is a lot of misinformation propagated by interested parties (like the FF industry etc.) that confuses the issues.
CC is the problem of the future – so far its effects have been modest – so motivation to spend lots of money to manage CC is less.
Q7: They say that renewable energy (RE) like wind and solar power will replace fossil fuels and cut down carbon di-oxide emissions. This should reduce global warming and control CC?
Not really. RE provides a very small percentage of our
energy consumption just now. About 80%
of global energy comes from FFs which emit CO2. Over the next 50 years, in the global context, the impact of RE will only be modest.
Moreover, CO2 stays in the atmosphere for over 100 years and CO2 that we have already put in there will continue to warm the world.
In order to reduce CO2 emissions and keep CC within sensible levels of 1 to 2oC rise in mean global temperature, serious action needs to be taken over the next 20 to 30 years, but much better to start today. RE will not be the major player in that.
Time to act is now, RE will come too late
Q8: COVID-19 pandemic forced lockdowns. This has resulted in reduced emissions. Has this reduced global warming?
Emissions were much reduced during COVID-19 but they are going up again as economies are beginning to open up.
So far in 2020, there has been some serious
reduction in the amount of CO2 emitted, but we
still added CO2 to the atmosphere.
This would have slowed GW by a tiny amount but not enough to make any serious difference.
Q9: Can
technology not help to solve the problem of CC?
Difficult to be sure. Technology is not always predictable.
CO2 build up has been relentless and for sure we have left it too late. We need to develop technologies which can
(a) Capture CO2 from the atmosphere and
store is safely
(b) Meet our energy needs w/o GHG
(greenhouse gas) emissions
People have suggested that CC may be
controlled by:
Blocking sunlight from reaching Earth (mirrors in space, spraying aerosols in the atmosphere etc.) - But watch out for unintended side effects of geo-engineering – I wouldn’t recommend it just now.
Q10: Is it too late to solve the CC conundrum?
Probably. Most scientific opinion is beginning to converge on mean global temperature rising by 3oC over the next 50 years provided nations start to take some serious action now. On the current trajectory, a rise of 4oC or even greater is highly likely - with some dire consequences. We have missed the opportunity of keeping GW below 2oC.
Q11: Should one just give up and hope for the
best?
Not advisable. To continue
as now (business as usual) will create many bad situations that will be
irreversible - some of them will cause runaway uncontrolled changes whose
consequences cannot be predicted at present.
In this scenario, CC might indeed become an existential threat for the human race.
Have you read?
7.75 Billion and 415 ppm; 4C Warmer World is Really Bad News : The paper explains why we need to act now.
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FINAL WORD: COVID-19 pandemic came suddenly, was treated as a crisis by national governments and swift action was taken by most countries to control the pandemic. Additional resources of 10 -15% of GDP were immediately found to tackle the pandemic.
Unfortunately, climate change has
never been treated as a crisis by most sectors of our society. Scientists have been ridiculed for their
predictions even though the climate crisis is unfolding to be a more urgent and
more severe problem than what was predicted 10 or 20 years ago. The goal of keeping global warming below 2oC
with aim to limit the temperature rise to 1.5oC before year 2100 has been shown to be totally unrealistic – the latest projections are that we shall
hit 1.5oC rise in GW within the next decade!
We need to educate ourselves and understand the extent
of the crisis – act responsibly to limit GW by our own actions and put pressure
on politicians and business interest to act decisively.
References: To understand the science of climate change,
you can look up my following six blog articles prepared specifically for non-specialists:
https://ektalks.blogspot.com/2019/11/making-sense-of-our-changing-climate-1.html
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