Downscaling reveals diverse effects of anthropogenic climate warming on the potential for local environments to support malaria transmission

The potential impact of climate warming on patterns of malaria transmission has been the subject of keen scientific and policy debate. Standard climate models (GCMs) characterize climate change at relatively coarse spatial and temporal scales. However, malaria parasites and the mosquito vectors respond to diurnal variations in conditions at very local scales. Here we bridge this gap by downscaling a series of GCMs to provide high-resolution temperature data for four different sites and show that although outputs from both the GCM and the downscaled models predict diverse but qualitatively similar effects of warming on the potential for adult mosquitoes to transmit malaria, the predicted magnitude of change differs markedly between the different model approaches. Raw GCM model outputs underestimate the effects of climate warming at both hot (3-fold) and cold (8–12 fold) extremes, and overestimate (3-fold) the change under intermediate conditions. Thus, downscaling could add important insights to the standard application of coarse-scale GCMs for biophysical processes driven strongly by local microclimatic conditions.     

The Contribution of Asteroid Dust to the Interplanetary Dust Cloud: The Impact of ULYSSES Results on the Understanding of Dust Production in the Asteroid Belt and of the Formation of the IRAS Dust Bands

Investigations of the zodiacal dust cloud give evidence for a significant contribution of asteroidal dust to the interplanetary dust cloud, a result which can now be compared to measurements of the ULYSSES dust detector during its passage of the asteroid belt. Especially we discuss the ULYSSES data with respect to the IRAS dust bands and consider geometric selection effects for the detector. From calculations of radiation pressure forces, we conclude that particles in the IRAS dust bands with massesm≥ 10⁻¹²g will stay in bound orbits after their release from asteroid fragmentation. This is already in the mass range (10⁻¹⁶–10⁻⁷g) of particles detectable with the dust detector onboard ULYSSES. The absence of these particles in the ULYSSES data cannot be explained exclusively in terms of their small detection probability. Thus we conclude that the size distribution of particles in the IRAS dust bands most probably cannot be continued to the submicrometer range. Concerning the global structure of the inner zodiacal cloud (i.e., about solar distancer< 3.5 AU) the ULYSSES data are not inconsistent with present models. Recent estimates of the total mass of the interplanetary cloud require a dust production rate of about 10¹⁴g/year of which a significant amount is assumed to result from the asteroids. Our estimate for the production of dust particles in an IRAS dust band, based on the assumption that the dust band results from a single destruction of an asteroid of 100 km size, yields a production rate of 10¹⁰g/year. Other models of the IRAS dust bands suggest production rates up to 10¹²g/year and also cannot provide a significant source of the dust cloud.     

Apparent and actual galaxy cluster temperatures

The redshift evolution of the galaxy cluster temperature function is a powerful probe of cosmology. However, its determination requires the measurement of redshifts for all clusters in a catalogue, which is likely to prove challenging for large catalogues expected from XMM-Newton , which may contain of the order of 2000 clusters with measurable temperatures, distributed around the sky. In this paper we study the apparent cluster temperature, which can be obtained without cluster redshifts. We show that the apparent temperature function itself is of limited use in constraining cosmology, and so concentrate our focus on studying how apparent temperatures can be combined with other X-ray information to constrain the cluster redshift. We also briefly study the circumstances under which the non-thermal spectral features can provide redshift information.     

Does temperature contain a stochastic trend: linking statistical results to physical mechanisms

By construction, the time series for radiative forcing that are used to run the 20c3m experiments, which are implemented by climate models, impart non-stationary movements (either stochastic or deterministic) to the simulated time series for global surface temperature. Here, we determine whether stochastic or deterministic trends are present in the simulated time series for global surface temperature by examining the time series for radiative forcing. Statistical tests indicate that the forcings contain a stochastic trend against the alternative hypothesis that the series are trend stationary with a one-time structural change. This result is consistent with the economic processes that impart a stochastic trend to anthropogenic emissions and the physical processes that integrate emissions in the atmosphere. Furthermore, the stochastic trend in the aggregate measure of radiative forcing also is present in the simulated time series for global surface temperature, which is consistent with the relation between these two variables that is represented by a zero dimensional energy balance model. Finally, we propose that internal weather variability imposed on the stochastic trend in radiative forcings is responsible for statistical results, which gives the impression that global surface temperature is trend stationary with a one-time structural change. We conclude that using the ideas of stochastic trends, cointegration, and error correction can generate reliable conclusions regarding the causes of changes in global surface temperature during the instrumental temperature record.     

Public engagement on solar radiation management and why it needs to happen now

There have been a number of calls for public engagement in geoengineering in recent years. However, there has been limited discussion of why the public should have a say or what the public can be expected to contribute to geoengineering discussions. We explore how public engagement can contribute to the research, development, and governance of one branch of geoengineering, solar radiation management (SRM), in three key ways: 1. by fulfilling ethical requirements for the inclusion of affected parties in democratic decision making processes; 2. by contributing to improved dialogue and trust between scientists and the public; and 3. by ensuring that decisions about SRM research and possible deployment are informed by a broad set of societal interests, values, and framings. Finally, we argue that, despite the nascent state of many SRM technologies, the time is right for the public to participate in engagement processes.