A little more than 40 years ago, the Apollo 8 astronauts, while
orbiting the Moon, photographed the whole Earth — its biosphere contrasting
with the sterile moonscape where the astronauts left their footprints. This
iconic image raised global awareness that “Spaceship Earth” was vulnerable,
and that sustaining it was an ecological imperative. Such concerns are in
even sharper focus today.
Our planet has existed for 45 million centuries. But this century is the first
in which one species — ours — could threaten the entire biosphere.
Throughout its history, Earth has been changing incessantly. Continents have
drifted; the ice cover has waxed and waned; species emerged, evolved and
became extinct. For 99.999 per cent of Earth’s history, these changes
proceeded on geological or glacial timescales. But their pace accelerated as
human beings came on the scene, engaging in agriculture, and industrial
activity.
Human populations are rising, more than doubling in the past 50 years, and
individuals are more technologically empowered. Our collective ecological
impact is growing with runaway speed. The fossil fuel we have already burnt
has consumed a million years’ growth of primeval forests. The consequent
build-up of carbon dioxide in the atmosphere — trapping heat by the
“greenhouse effect” — is warming the world and altering weather patterns.
By 2050, the world’s population seems likely to exceed nine billion. All will
aspire to secure supplies of food and energy in a world in which climate
change will aggravate pressure on water and other natural resources. Other
“threats without enemies” confront us too. High among these is the threat to
biological diversity caused by rapid changes in land use, deforestation and
climate change. There have been five great extinctions in the geological
past; human actions are causing a sixth. The extinction rate is 1,000 times
higher than normal. We are destroying the book of life before we have read
it.
Biodiversity — manifested in forests, coral reefs, marine blue waters and all
other ecosystems — is often proclaimed as a crucial component of human
wellbeing: we are clearly harmed if fish stocks dwindle to extinction; there
are plants whose gene pool might be useful to us. And large-scale
destruction of the rainforests would accelerate global warming. But for
environmentalists these “instrumental” — and anthropocentric — arguments are
not the only compelling ones. For them, preserving the richness of our
biosphere has value in its own right, over and above what it means to us
humans.
Fossil fuel consumption in Europe and the US is now greatly augmented by Asia;
annual CO2 emissions are rising. But the consequent shifts in weather
patterns (and of rising sea levels) will impact most greviously on those
least able to adapt, and on countries that have themselves contributed
minimally to global CO2 emission.
“Business as usual” would lead, by this century’s end, to a carbon
concentration in the atmosphere three times the pre-industrial level, which
would, with very high confidence, lead to severely disruptive climate
change. There is real urgency in reversing the year-by-year rise in annual
emissions. Unless the rising curve can be turned around by 2020, atmospheric
concentration will irrevocably reach a threatening level.That is why the G8
and the EU have espoused a target of cutting global CO2 emissions to half
the 1990 level before 2050. This target corresponds to 2 tons of CO2 a year
from each person on the planet. For comparision, the present US level is 20,
the European figure about 10, and the Chinese already more than 4. To
achieve this target without stifling economic growth in the developing world
is a huge challenge.
After 2050, the world may have shifted to a low-carbon economy based on
greater energy efficiency and advanced “renewable” technology. (We could
derive our power from solar energy collected in the Sahara, and distributed
Europe-wide via a “smart grid”). Parts of the developing world can leapfrog
directly into “clean” technology, just as they've adopted mobile phones and
bypassed landlines. It should be a priority to speed up this transition.
Tackling climate change is a daunting poltical challenge for two reasons .
First, unlike most pollution, where the impact is localised, the
consequences for Britain’s climate of each ton of CO2 are as great if it
comes from China or from here, and vice versa. Co-ordinated international
action is essential. Moreover, there are long time-lags: the climatic
consequences of our present actions build up over decades, even centuries.
The worst downsides from our failure to act will fall on our grandchildren
rather than us. There are always pressures to discount the future too
heavily and for the short-term to trump the long-term.
There will be no effective action unless worldwide public opinion gives
priority to saving the global environment. This won’t happen unless there is
a sufficiently firm consensus on the underlying science: how serious the
threats are, and how best to abate them. The Earth’s atmosphere, oceans and
biota interact in complex ways about which we still have a lot to learn.
When he spoke in Cambridge some years ago, the Prince of Wales said:
“Scientists do not fully understand the consequences of our many-faceted
assault on the interwoven fabric of atmosphere, water, land and life in all
its biological diversity. Things could turn out to be worse than the current
scientific best guess. In military affairs, policy has long been based on
the dictum that we should be prepared for the worst case. Why should it be
so different when the security is that of the planet and our long-term
future? “ The presence of Nobel-class scientists from other specialities at
the St James’s Palace symposium is important for two reasons. First, they
are the most discerning and critical audience one could imagine. Therefore
current ideas on climate change will be “battle tested” by some of the
sharpest scientific minds in other fields. Second, it is absolutely clear
that a transition to a sustainable world will require innovation across the
entire scientific spectrum. Experts in clean energy technology, food
production and social science will all need to step up to the plate — and
attract private and public sector investment to back them Scientists,
governments and the international business community should focus on the
build-up to the Copenhagen conference in December. If this crucial
opportunity is not squandered, hopes will rise that our civilisation can,
without trauma or disaster, segue towards a sustainable world with efficient
agriculture, a low-carbon economy, and a stable (or slowly falling)
population.
