4 Predictions for life: Natural systems

What impacts will future climate change and ocean acidification have on life?

You saw in Session 2 that many marine species such as fish are migrating their habitats from one region to another much faster than terrestrial species. This is because there are fewer physical barriers preventing them from adapting in this way.

Figure 9 shows the IPCC (2013) estimates of how fast different species can migrate, along with the average speeds necessary under different RCP scenarios (the ‘climate velocity’, the rate of movement of the climate across the landscape). Freshwater molluscs can migrate rapidly, with the white bar extending far above most predicted climate change. But small terrestrial species and, of course, vegetation, are much more limited. For them, migration speeds may not be sufficient to respond, i.e. to adapt, to RCP6.0 or RCP8.5 scenarios of climate change. Those that cannot adapt will see their population numbers decrease or become extinct in part or all of their ranges.

Figure 9 Who can outrun climate change? Maximum speed at which species can migrate, along with corresponding speeds required for each RCP scenario (adapted from IPCC, 2014).

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Figure 9 is a column bar chart indicating the range of speeds that different animal and plant species can migrate away from their current habitats. The y or vertical axis represents the maximum speed at which species can move (in kilometres per decade), from 0 to 100. The x or horizontal axis shows various species including trees, herbaceous plants, rodents and freshwater molluscs. Not all of the details are required, but as an example, trees might migrate at speeds of (0 - 15) km per decade whilst carnivorous mammals might migrate at speeds from (10 - 100 km per decade).

The graph also indicates speeds needed to survive the various scenarios e.g. RCP8.5 Global average scenarios require a speed of 20 km per decade, which is in range for all species here except trees; RCP8.5 scenarios over flat areas require a speed of over 70 km per decade, achievable by carnivorous mammals and plant -feeding insects but not rodents, primates or any plants shown.

Figure 9 Who can outrun climate change? Maximum speed at which species can migrate, along with corresponding speeds required for each RCP...