Current targets in international negotiations on climate change will not lead to a world with healthy coral reefs, according to the CRTR Program’s Professor Hoegh-Guldberg.
Delegates attending technical workshops in the lead up to the GEF International Waters Conference heard today from Professor Hoegh-Guldberg about two worlds – one in which coral reefs can thrive; and another in which the effects of climate change will prevent coral reefs from growing or responding well to stress.
Coastal resources including mangroves, seagrass meadows, soft sediment communities, rocky shores and coral reefs supply food, building materials, income, coastal stabilisation and protection, as well as possessing high cultural and spiritual values. They support up to 500 million people, and underpin billion dollar industries (eg fisheries, tourism).
Key threats faced by coral reefs in particular include over-exploitation from fisheries and tourism; inappropriate coastal development; and climate change which amplifies the other threats.
Reefs already stressed by pollution and sedimentation will not recover from bleaching events associated with warming oceans. World-wide 16% or all coral reefs were killed in the bleaching event of 1998. In the West Indian Ocean, where reefs are under a range of pressures, a staggering 46% of reefs died and there has been little recovery after almost a decade.
Increasing ocean acidification, associated with rising atmospheric CO2 levels, could spell “double trouble” for reefs, as it compounds the effects of bleaching and means that reefs will not have appropriate conditions for growth or survival. Indeed, calcification of reefs has already decreased by an estimated 20% since 1990.
The current emission targets that international negotiators have committed do not solve the problem, according to Professor Hoegh-Guldberg.
To avoid disaster for coral reefs, and the ecosystems and people that rely on them, negotiators must consider scenarios that bring emissions down to 5% of today’s levels by 2050 to have any chance of stabilizing CO2 at 450 ppm.