Rome, Italy
June 17, 2009
As rapidly rising temperatures in
Africa threaten to scorch local varieties of maize and other
food staples, the food security of many Africans will depend on
farmers in one country gaining access to climatically suitable
varieties now being cultivated in other African nations, and
beyond, according to
a peer-reviewed study published in
Global Environmental Change.
But the study, conducted by researchers at Stanford University's
Program on Food Security and the Environment and the Rome-based
Global Crop Diversity Trust,
warns that long-standing neglect of African crop collections
held in genebanks means that breeders today don't have access to
all of the varieties of Africa's primary cereal crops—maize,
millet and sorghum—that are likely to be most helpful in
allowing farmers to adapt to climate change.
"When we looked where temperatures are headed, we found that for
the majority of Africa's farmers, climate change will rapidly
move conditions beyond the range of anything they've
experienced," said Marshall Burke, Program Manager at the
Program on Food Security and the
Environment at Stanford University. "A central challenge
will be finding crop varieties that can thrive – or at least
survive – at these hotter temperatures."
Many African farmers could potentially find crop varieties in
other African countries where current temperatures and
conditions are similar to what they will face in the future. But
researchers are particularly concerned about six
countries—Senegal, Chad, Mali, Burkina Faso, Niger and Sierra
Leone—where future conditions will be unlike anything African
farmers have ever encountered. And they said immediate action is
needed to develop new crop varieties that will allow these
countries to adapt.
"This is not a situation like the failure of the banking system
where we can move in after the fact and provide something akin
to a bailout," said Cary Fowler, head of the Global Crop
Diversity Trust. "If we wait until it's too hot to grow maize in
Chad and Mali, then it will be too late to avoid a disaster that
could easily destabilize an entire region and beyond."
The release of the study comes amid growing concerns that an
international climate change agreement to be finalized this
December in Copenhagen will focus mainly on carbon emissions and
not on helping poor populations adapt to such things as
dramatically altered growing conditions.
For example, at an international conference last week in Bonn,
the executive secretary of the United Nations Framework
Convention on Climate Change noted that while Africans will bear
the brunt of the impact, they have "benefited the least from the
current climate change regime." He pointed out that funds
established to help developing countries adapt to climate change
"remain largely empty."
Researchers from Stanford and the Global Crop Diversity Trust
said there is a particularly urgent need to address the
situation in Africa because the potential changes are so
dramatic and are likely to occur even if there are steep
reductions in carbon emissions.
At issue is the fact that most crop varieties cultivated on
African farms are "landraces"—or traditional varieties—that have
been selected by farmers over the centuries due to their unique
suitability to local growing conditions. But Burke and his
colleagues report that by 2050, due to global warming,
temperatures during the growing season in nearly all African
countries will be "hotter than any year in historical
experience" for that region, leaving that once well-adapted
local variety suddenly unable to cope, or at least adapt quickly
enough.
Seeking a potential solution to this problem, the researchers
documented the "novel" climates expected to emerge in each
African country by 2050 and compared them with present
conditions across the continent. What they found is that for the
majority of countries, while those novel climates will be
different than anything they've ever experienced within their
borders, in many cases the climates will be similar to what
exists today in other nations.
For example, in Lesotho, a country with one of Africa's coolest
climates, farmers may find their local varieties of maize
suffering in the increasing heat. The answer to their problems
might lie in the maize varieties now being cultivated in Mali,
one of Africa's hottest countries.
"We know there are local varieties of maize, millet, sorghum and
other crops genetically endowed with traits that would be of
enormous benefit in helping African farmers in that country and
others, adapt to climate change," said Luigi Guarino, Senior
Science Coordinator at the Global Crop Diversity Trust. "But the
genebank collections from many areas that are likely to have the
widest range of diversity are either incomplete or
non-existent."
The researcher found that there is a "set of countries whose
current climate" is very similar "to many future climates." But
they note that the landraces from these countries, which include
Sudan, Nigeria, Cameroon and Mozambique, "are poorly represented
in national and international genebanks." For example, there are
ten African countries where the current growing conditions for
maize are very similar to what many African countries will soon
face. But few landraces from these areas are to be found in
major genebanks.
"These countries are particularly high priorities for urgent
collection and conservation of maize genetic resources," the
researchers advise.
Meanwhile, the study identified a "worrying set" of six
countries—Senegal, Chad, Mali, Burkina Faso, Niger and Sierra
Leone—where future climates may end up warmer than anything
currently found on the continent. According to the study, "for
these countries, there is a much smaller potential pool of
foreign genetic resources in which to seek heat tolerance, at
least within Africa." One consequence, the researchers note, is
that the countries may no longer be able to grow maize, which is
generally more heat sensitive, and have to switch to food crops
like sorghum and millet that are often more heat-tolerant.
Nonetheless, the study concludes that for most countries, there
are solutions available, if the collective plant genetic
resources of Africa can be effectively "managed and shared."
"We have seen in recent years substantial progress in conserving
and sharing plant genetic resources, but the problems we are
facing with climate change demand a much stronger commitment to
international collaboration," said Fowler. "This study makes it
clear that crop diversity is a prerequisite for successful
adaptation to climate change in Africa."
The mission of the Global
Crop Diversity Trust is to ensure the conservation and
availability of crop diversity for food security worldwide.
Although crop diversity is fundamental to fighting hunger and to
the very future of agriculture, funding is unreliable and
diversity is being lost. The Trust is the only organization
working worldwide to solve this problem.
Stanford's Program on Food
Security and the Environment aims to generate innovative
solutions to the persistent problems of global hunger and
environmental damage from agricultural practices worldwide.
Source: Burness
Communications |
|
Shifts in African crop
climates by 2050, and the
implications for crop
improvement and genetic
resources conservation
Marshall B. Burkea, David B.
Lobella and Luigi Guarinob
Science Direct
Abstract
Increased understanding of the
substantial threat climate
change poses to agriculture has
not been met with a similarly
improved understanding of how
best to respond. Here we examine
likely shifts in crop climates
in Sub-Saharan Africa under
climate change to 2050, and
explore the implications for
agricultural adaptation, with
particular focus on identifying
priorities in crop breeding and
the conservation of crop genetic
resources. We find that for
three of Africa's primary cereal
crops – maize, millet, and
sorghum – expected changes in
growing season temperature are
considerable and dwarf changes
projected for precipitation,
with the warmest recent
temperatures on average cooler
than almost 9 out of 10 expected
observations by 2050. For the
“novel” crop climates currently
unrepresented in each country
but likely extant there in 2050,
we identify current analogs
across the continent. The
majority of African countries
will have novel climates over at
least half of their current crop
area by 2050. Of these
countries, 75% will have novel
climates with analogs in the
current climate of at least five
other countries, suggesting that
international movement of
germplasm will be necessary for
adaptation. A more troubling set
of countries – largely the
hotter Sahelian countries – will
have climates with few analogs
for any crop. Finally, we
identify countries, such as
Sudan, Cameroon, and Nigeria,
whose current crop areas are
analogs to many future climates
but that are poorly represented
in major genebanks – promising
locations in which to focus
future genetic resource
conservation efforts.
Access to full article |
|