68
The most recent estimates indicate that human activities are cur-
rently responsible for annual global carbon emissions of around
7–10,000 Tg C yr
–1
, of which around 1,500 Tg C or around 15–
20% is the result of land use change. The remaining emissions
are from fossil fuel use and cement production (Canadell
et al.
,
2007). This has led to an average annual rate of increase of CO
2
concentrations in the atmosphere of 1–2 ppm or up to 2,000 Tg C
yr
–1
for the years 1995–2005 compared with around 1.25 ppm for
the years 1960–1995 (IPCC, 2007b; Houghton, 2007).
Green carbon:
Reducing deforestation rates by 50% by 2050
and then maintaining them at this level until 2100 would avoid
the direct release of up to 50 Gt C this century or approximately
555 Tg C yr
–1
, which is equivalent to 12–15% of the emissions
reductions needed to keep atmospheric concentrations of carbon
dioxide below 450 ppm (Trumper
et al.
, 2009).
Blue carbon:
According to this report, protection, improved man-
agement and restoration of the ocean’s blue carbon sinks would
result in preventing the annual loss of up to 450 Tg C yr
–1
, or equiva-
lent to a corresponding 10% of the reductions needed.
Combined with the green carbon – REDD – the effect would be at
least 20–25% of the emission reductions needed – with huge ben-
efits to food security, water resources, biodiversity – and the cre-
ation of jobs and incomes. But this would require a similar “REDD”
programme for oceans as has been established for rainforests – a
blue carbon fund.
Fact box 8. A 25% emission reduction could be gained from green and blue carbon
