Categories
Climate

Medieval Warm Period local or global?

Global warming is directly influencing humans through surface temperatures, but most heat uptake occurs in the ocean. It is therefore interesting how the ocean heat content has changed over time. In a recent article in Science Rosenthal et al. present a temperature record of western equatorial Pacific subsurface and intermediate water masses over the past 10,000 years that shows that heat content varied in step with both northern and southern high-latitude oceans. The findings support the view that the Holocene Thermal Maximum, the Medieval Warm Period, and the Little Ice Age were global events, and they provide a long-term perspective for evaluating the role of ocean heat content in various warming scenarios for the future. This result conflicts with the one of Pages 2k consortium in Nature Geoscience earlier this year where they state: “There were no globally synchronous multi-decadal warm or cold intervals that define a worldwide Medieval Warm Period or Little Ice Age”.

Categories
Climate malaria vector-borne diseases

Inherited selection bias, climate models, and vector borne diseases

Empirical cumulative distribution function of warming per year [C] for 1984-2013 (left) and 1997-2013 (right). The distribution function was estimated using 38 CMIP5 models with a total of 344 simulations. The grey dot shows the actual warming rate (based on HadCRUT.4.2) which is lower than 95% of the climate model realisations for the 30 year period (1984-2013), and lower than 99% of the climate model realisations for the 15 year period (1997-2013). 1961-1990 was used as the baseline period.
This week I am discussing the “pause” in global warming, if the IPCC near term surface temperature projections might be too high, and how such errors influence projected changes in vector borne diseases. The full post can be read at Biomedcentral┬┤s Bugbitten blog.