Editorials
Climate change
BMJ 2014; 349 doi: http://dx.doi.org/10.1136/bmj.g5945 (Published 01 October 2014) Cite this as: BMJ 2014;349:g5945- Fiona Godlee, editor in chief, The BMJ
When The BMJ started publishing articles on climate change, some readers told us to stick to our knitting (www.bmj.com/content/332/7554/0.7/rapid-responses).
“What did this have to do with medicine?” they asked. And wasn’t
climate change a myth, a result of natural climatic variation, nothing
to do with human activity? There were surely more immediate challenges
that The BMJ and its readers should be focusing on.
We
listened politely but carried on, convinced of the threat to human
health and survival. With others we set up the Climate and Health
Council (climateandhealth.org). We published editorials and articles (thebmj.com/content/climate-change),
co-hosted conferences and seminars, lobbied funders, talked to policy
makers and politicians, and worked with the BMA, the royal colleges, and
their equivalents in other countries, all the time worrying that this
was not enough. Our hope was to encourage doctors and other health
professionals to take a lead in tackling climate change.
Now
we have gone a step further, with the publication of an article that
contains no medicine or healthcare at all. “The science of anthropogenic
climate change: what every doctor should know” is pure climate science.1
Why? Because if we doctors are to become effective advocates against
climate change, a better understanding of the science will help us.
As
most readers will know, the news is not good. With a high degree of
certainty the Intergovernmental Panel on Climate Change (IPCC) has
concluded in its fifth report that the world is getting hotter and that
human activity is mainly to blame. Global average temperatures have
risen by about 0.5°C in the past 50 years and by 0.8°C from
pre-industrial times. The effect of these higher temperatures on weather
systems is already being felt. The IPCC reports that it is highly
likely that global warming is causing climate change, characterised by
more frequent and intense temperature extremes, heavier rainfall events,
and other extreme weather events. Sea levels are rising as a result of
the thermal expansion of the oceans and the melting of polar icecaps and
glaciers.
The headlines should come as no surprise, but
the detail may prove instructive. Higher seas mean more frequent and
extreme tidal surges, coastal flooding, and the salination of vital
fresh water supplies. Warmer air carries more moisture, leading to more
extreme rainfall events. But warmer air also reduces the amount of
moisture in the soil, contributing to soil erosion and flash flooding.
As
for the main underlying cause, the IPCC is clear: it is the
accumulation of anthropogenic carbon dioxide in the atmosphere. Other
gases and aerosols are also to blame, especially methane and nitrous
oxide, and particulate black carbon. But carbon dioxide is long lived.
Once released into the atmosphere it stays around for centuries.
Deforestation makes this worse.
Best and worst cases
What
of the future? The IPCC has modelled four scenarios varying with the
extent and nature of future emissions. The best case (the so called RCP
(representative concentration pathway) 2.6) sees a radical cut in
greenhouse gas emissions, starting almost immediately. Even then global
warming would continue, leading to average temperatures of almost 2°C
above pre-industrial levels. The worst case (RCP 8.5) is “business as
usual” with unabated emissions, which would lead to a further rise by
2100 of 3.7°C above the average at the beginning of this century and
more than 4°C higher than pre-industrial levels. As our Analysis authors
explain, regional variations mean that in some parts of the northern
continents temperatures would increase by more than 10°C.
Writing last week in the Lancet,2
Andy Haines and colleagues emphasised that such huge temperature rises,
and the consequent severe climate instability, would take us into what
is being called the “afterlife” threshold, “where the impact on humanity
is so great as to be a discontinuity in the long-term progression of
humanity.” In other words, the effects would be catastrophic.
The diagnosis
If
climate change is a symptom of a planet in distress, what is the
disease? Speaking last month in Geneva, Christiana Figueres, executive
secretary of the United Nations Framework Convention on Climate Change,
was uncompromising. The disease is “our unbridled dependency on fossil
fuels,” which shows no sign of abating. Despite the rhetoric from the
world’s major polluters at last week’s United Nations meeting on climate
change in New York,3
rates of carbon emission are accelerating. Our Analysis article
explains that the amount of carbon we can still afford to emit if we are
to stay below 2°C of warming compared with pre-industrial levels (our
“carbon budget”) will be exceeded in the next 25-30 years.
Calls
for organisations to disinvest from fossil fuels and reinvest in
renewable energy are gaining momentum. The president of the World Bank,
Jim Yong Kim, himself a doctor, propelled this idea into the mainstream
by suggesting in a speech at the World Economic Forum that carbon
emissions could be tackled through divestment and taxation.4 Groups such as the Global Climate and Health Alliance (www.climateandhealthalliance.org) have been quick to take up the call. Archbishop Desmond Tutu has called divestment a moral imperative.5
The BMA agreed to divest at its annual meeting in June, and major
universities and funding bodies have also signed up, the Rockefeller
family and the World Council of Churches being among the most recent.6
Figueres
was speaking at the first WHO conference on health and climate, where
health ministers joined delegates from intergovernmental and
non-governmental organisations in an extraordinary show of consensus.
All agreed with WHO director general Margaret Chan’s assessment that
climate change is the greatest threat to public health and the defining
issue of the 21st century. The conference gave a clear warning: that
without adequate mitigation and adaptation, climate change poses
unacceptable risks to public health worldwide.7
Health benefits of acting on climate change
In
this unequal battle with big business and political inertia we have a
crucial card to play: the knowledge that much of what we need to do to
tackle climate change will bring substantial benefits to health. Burning
fossil fuels causes about seven million premature deaths from indoor
and outdoor air pollution. Smog in Beijing and other major cities is
alerting the public and waking up our politicians in ways that the more
invisible threat from carbon dioxide emissions has failed to do.
Healthcare is itself a major emitter of greenhouse gases and has a
responsibility to get its own house in order, to avoid the paradox of
doing harm while seeking to do good.8
Also in our hand is the substantial health dividend of more active and
sustainable low carbon lifestyles: lower rates of obesity, heart
disease, diabetes, and cancer.9
WHO
has shown important leadership on climate change but has stopped short
of declaring a global public health emergency. This may be
understandable with Ebola raging. But it is what WHO should now do.
Deaths from Ebola infection, tragic and frightening though they are,
will pale into insignificance when compared with the mayhem we can
expect for our children and grandchildren if the world does nothing to
check its carbon emissions. And action is needed now.
Notes
Cite this as: BMJ 2014;349:g5945
Footnotes
- Competing interests: At the request of WHO I acted as moderator at its first conference on health and climate in Geneva, 27-29 August 2014.
- Provenance and peer review: Not commissioned; peer reviewed.
