The concentration of atmospheric CO2 has been increasing since the mid-1800s to the present day (Fig. 3)13.
CO2 concentration rises in winter and declines in summer, mainly in response to the seasonal growth of terrestrial vegetation. Since the early 1960s, the amplitude of this oscillation has increased by 20% in Hawaii and by 40% in the Arctic14. The increases are accompanied by phase advances of about seven days during the declining part of the cycle. Increasing climate or organisms that are highly mobile at some stage of their life cycle (such as flying insects, birds and marine invertebrates). However, there are some instances of apparent shifts in distribution of less mobile species, such as
terrestrial mammals, that are also correlated with recent climate trends.