Search

The climate shift towards wetter conditions at the transition from Subboreal to Subatlantic in NW-Europe (ca 850 cal. yrs BC; caused by a decline of solar activity), is also evident in South Siberia. Areas that initially were hostile semi-deserts changed into attractive steppe landscapes with a high biomass production, and therefore high carrying capacity. We focus on south-central Siberia where an acceleration of cultural development and an increase in the density of nomadic Scythian populations took place shortly after 850 BC. We hypothesize a causal relationship between the Scythian expansion and migration, and the early Subatlantic shift towards increased humidity.

The climate shift towards wetter conditions at the transition from Subboreal to Subatlantic in NW-Europe (ca 850 cal. yrs BC; caused by a decline of solar activity), is also evident in South Siberia. Areas that initially were hostile semi-deserts changed into attractive steppe landscapes with a high biomass production, and therefore high carrying capacity. We focus on south-central Siberia where an acceleration of cultural development and an increase in the density of nomadic Scythian populations took place shortly after 850 BC. We hypothesize a causal relationship between the Scythian expansion and migration, and the early Subatlantic shift towards increased humidity.

Het IPCC laat er weinig twijfel over bestaan: de mens is verantwoordelijk voor de toename van broeikasgassen en is daarmee schuldig aan een onnatuurlijke opwarming. De invloed van het IPCC op de regeringen van de geïndustrialiseerde landen is groot. Het Kyoto-protocol moet leiden tot een reductie van de uitstoot van kooldioxide, maar veel zal dat niet helpen. In dit artikel komt de vraag aan de orde of de IPCC conclusies wel juist zijn. Biogeologisch onderzoek wijst namelijk op een heel belangrijke rol van de zon op klimaatveranderingen in het verleden

RIVM rapport:Abstract niet beschikbaar, During the last century human-induced changes in atmospheric deposition, land use and water management greatly affected growing conditions of plant and animal species and dramatic changes in biological diversity in natural ecosystems have been observed. Predicted climate change as a result of increasing atmospheric CO2 concentrations may further threaten biodiversity. This project aimed at answering: what have been the effects of changes in atmospheric CO2 concentrations, temperature, precipitation and atmospheric nitrogen deposition levels on diversity and distribution patterns of vascular plants and Lepidoptera (moths) species in the past; and what will these effects be in the coming decades? The first subproject described the changes in occurrence and phenology of species that have occurred during the 20th century in the Netherlands and related these changes to possible environmental causes. The second subproject focussed on rain-fed bogs in order to study the relation between climate and species composition over a time period of several centuries. The third subproject modelled the effects of climate change on ecosystem variables that are known to have major impacts on plant diversity such as nitrogen supply, soil acidity, soil moisture and light conditions at soil surface level. The results of the project demonstrate that climate change already has been a strong contributing factor to changes in the occurrence and the phenology of plant species and Lepidoptera species in the Netherlands. The historic analysis of rain-fed peat bogs also demonstrated the impact of climate change on changes in plant species occurrence. The model studies indicate that future climate change may have further consequences for ecosystem processes and species diversity.