Climate velocities and species tracking in global mountain regions

Mountain ranges harbor high concentrations of endemic species and are
indispensable refugia for lowland species under anthropogenic climate
change1,2. Forecasting biodiversity redistribution hinges on assessing
whether species can track shifting isotherms as climate warms3,4. However,
a global analysis of isotherm shift velocities along elevation gradients
is hindered by the scarcity of weather stations in mountainous regions5.
We address this by mapping the lapse rate of temperature (LRT) across
mountain regions globally using satellite data (SLRT) and laws of
thermodynamics to account for water vapour6 (i.e., the moist adiabatic
lapse rate: MALRT). Dividing the rate of surface warming from 1971 to 2020
by either the SLRT or MALRT, we provide the first maps of vertical
isotherm shift velocities. We identify 17 mountain regions with
exceptionally high vertical isotherm shift velocities (> 11.67 m/yr
for the SLRT, > 8.25 m/yr for the MALRT), predominantly in dry
areas but also in wet regions with shallow lapse rates like Northern
Sumatra, the Brazilian Highlands, and Southern Africa. By linking these
velocities to species range shift velocities, we report instances of close
tracking in mountains with lower climate velocities. However, many species
lag behind, suggesting persisting range shift dynamics even if we manage
to curb climate change trajectories. Our findings are vital for devising
global conservation strategies, particularly in the 17 high-velocity
mountain regions we identified. References Rahbek, C. et al. Building
mountain biodiversity: Geological and evolutionary processes. Science 365,
1114-1119 (2019). Rahbek, C. et al. Humboldt’s enigma: What causes global
patterns of mountain biodiversity? Science 365, 1108-1113 (2019). Chen, I.
C., Hill, J. K., Ohlemuller, R., Roy, D. B. & Thomas, C. D. Rapid
Range Shifts of Species Associated with High Levels of Climate Warming.
Science 333, 1024-1026 (2011). Lenoir, J. et al. Species better track
climate warming in the oceans than on land. Nature Ecology &
Evolution, 1-16 (2020). Pepin, N. et al. Elevation-dependent warming in
mountain regions of the world. Nat Clim Change 5, 424-430 (2015). Holton,
J. R. & Hakim, G. J. An introduction to dynamic meteorology. Vol.
88 (Academic press, 2012).