Population, climate change and food security, Karin Kuhlemann, Population Matters
Population, climate change andPopulation, climate change and
food securityfood security
The century of living dangerouslyThe century of living dangerously
Karin Kuhlemann – Population MattersKarin Kuhlemann – Population Matters
UN projections (2012)
• Global population to rise by. 3.7Bn by the end of this century?
• People assume we live in the “medium variant” world – 9.6Bn in
2050 and 10.9 Bn by 2100
• UN projections assume reductions in fertility for all variants – they
are not BAU estimates.
• High variant estimate is not a ceiling; implies a population of 10.9
Bn in 2050 and 16.7 Bn in 2100
• The “low-variant” projection, would produce a population of 8.3
billion in 2050
• The BAU estimate (no change in fertility) projects a world of nearly
30 Bn by 2100
• Small variations in fertility make a HUGE difference over time
• The ‘gap’ between the high and medium variants, and the medium
and low variants, is only half a child per woman on average
Growing food needs
• Each human being needs, on average, at least
2200-2500 calories per day
• Population growth means the minimum amount
of food we need as a global community is rising
• Rising prosperity => rising meat consumption
• If these trends continue, we will need to double
the amount of crops we grow by 2050
• Arable land per capita has been declining over
time; decrease hasn’t been sharper due to
ongoing deforestation activity
Can we double crop outputs?
• Natural sources of plant nutrition insufficient to sustain current
levels of food production.
• Use of synthetic nitrogen fertilizer has increase nine-fold since the
1960s and phosphorus use has tripled. It is projected that the
world will increase its demand and use of fertilizers in the next
40 years by 40 percent to 50 percent. [UN, 2013]
• Fertilizer run-off major source of water pollution worldwide.
• Nitrous oxide is emitted when people add nitrogen to the soil
through the use of synthetic fertilizers. It has 300 times the
warming potential of CO2. [US Environmental Protection
• A quarter of the world’s agricultural land is highly degraded;
another 8% has moderate degradation, 36 per cent is classed as
stable or slightly degraded and 10 per cent ranked as
“improving.” [FAO 2011]
• 70% of world’s freshwater withdrawal is used for agriculture
• Water use has grown nearly twice as fast as population.
• Around 700 million people in 43 countries suffer from water
scarcity. [UN, 2006]
• By 2025, 1.8 billion people will be living in countries or regions
with absolute water scarcity, and two-thirds of the world's
population could be living under water stressed conditions.
• Water scarcity in some arid and semi-arid places will displace
between 24 million and 700 million people.
• Sub-Saharan Africa has the largest number of water-stressed
countries of any region.
• Latest IPCC report acknowledges that growth in emissions is driven
by growth in population numbers and consumption
• Agriculture and fisheries highly dependant on stable climate
• Agriculture is among the greatest contributors of climate change,
emitting more greenhouse gases than all our cars, trucks and
airplanes combined. Emissions set to rise by 30% by 2050. [FAO,
• Climate change could cause median crop yields to drop by 2% per
decade going forwards
• Food production from maize, soybeans, wheat and rice may fall by
as much as 43 percent by the end of this century
• That’s to say nothing of the effect of changing precipitation
patterns and more frequent droughts
What can be done to improve food
security in the face of climate change?
• We are entering an era of living dangerously as a global
• There is simply no guarantee we will be able to feed a
much larger global population
• One in 8 people chronically hungry today (FAO, 2012)
• Efforts at adaption to further population growth likely to
hasten climate change.
• Reducing fertility rates globally would have the most
impact on improving food security and our chances of
adaptation/mitigation to climate change.
• We do not, in fact, have all the time in the world to see
what happens to population numbers if we do nothing.
• Population growth is not inevitable – but it takes a very
long time to reverse through reductions in fertility
• Population momentum can keep the population
growing for decades after fertility rates reach
replacement or sub-replacement
• Population became a “taboo” topic since the
International Conference on Population and
Development (Cairo, 1994)
• Funding for family planning services has fallen sharply
• Some 200-250 million women worldwide don’t have
access to modern family planning methods
We need to talk about population
• Something as serious as this needs to be talked
about openly by all (including scientists!)
• If we care about human rights, we need to care
about population growth
• If we are trying to ensure food security for all, we
need to talk about population growth
• If we are trying to mitigate the effects of climate
change (and stop making it worse), we need to
talk about population.