Projected changes in the organic carbon stocks of cropland mineral soils of European Russia and the Ukraine, 1990–2070

Abstract

In this paper, we use the Rothamsted Carbon Model to estimate how cropland mineral soil carbon stocks are likely to change under future climate, and how agricultural management might influence these stocks in the future. The model was run for croplands occurring on mineral soils in European Russia and the Ukraine, representing 74 Mha of cropland in Russia and 31 Mha in the Ukraine. The model used climate data from the HadCM3 climate model, forced by four Intergovernmental Panel on Climate Change (IPCC) emission scenarios representing various degrees of globalization and emphasis on economic vs. environmental considerations. Three land use scenarios were examined, business as usual (BAU) management, optimal management (OPT) to maximize profit, and soil sustainability (SUS) in which profit was maximized within the constraint that soil carbon must either remain stable or increase. Our findings suggest that soil organic carbon (SOC) will be lost under all climate scenarios, but less is lost under the climate scenarios where environmental considerations are placed higher than purely economic considerations (IPCC B1 and B2 scenarios) compared with the climate associated with emissions resulting from the global free market scenario (IPCC A1FI scenario). More SOC is lost towards the end of the study period. Optimal management is able to reduce this loss of SOC, by up to 44% compared with business as usual management. The soil sustainability scenario could be run only for a limited area, but in that area was shown to increase SOC stocks under three climate scenarios, compared with a loss of SOC under business as usual management in the same area. Improved agricultural soil management will have a significant role to play in the adaptation to, and mitigation of, climate change in this region. Further, our results suggest that this adaptation could be realized without damaging profitability for the farmers, a key criteria affecting whether optimal management can be achieved in reality.

Will European soil‐monitoring networks be able to detect changes in topsoil organic carbon content?

“…Table 4 shows that for most of the countries, detectable changes range from 1% to 10% in the base estimate of stock. These changes are very similar to the projected changes (about 6%) simulated by Smith et al (2007) in mineral soil C of European Russia and Ukraine's croplands and grasslands over the last 10 years of their simulation (2060)(2061)(2062)(2063)(2064)(2065)(2066)(2067)(2068)(2069), under the business-as-usual scenario. This suggests that over about 10 years most of the existing SMNs could be used to verify such changes.…”

Elevated CO2maintains grassland net carbon uptake under a future heat and drought extreme

“…Although climatic extremes are likely to become more frequent and more severe toward the end of the century, the current Earth system models do not simulate adequately the impacts of climate extremes on biogeochemical cycles (47) and still have large uncertainties in parameterizing regional responses to such events and often provide contrasting results (47)(48)(49)(50). Our experiment highlights the importance of accounting for interactions between drivers of global change, their seasonality effects, and the importance of poststress recovery processes for more accurate model predictions of the future C budgets of grasslands.…”

The influence of climate change on the soil organic carbon content in Italy from 1961 to 2008

“…According to Post et al (2001) extensive changes in land use and agricultural activities which have occurred during the last 200 years have transformed soils into net sources of atmospheric CO 2 . Recent research works have postulated that past changes in land-use history and land management have been the main reasons for the SOC losses, rather than higher temperatures and changes of precipitation resulting from climate change (Bellamy et al, 2005;Gardi and Sconosciuto, 2007;Smith et al, 2007aSmith et al, , 2007bSmith, 2008;Minasny et al, 2010). Smith et al (2007c) reported that only about 10-20% of observed soil carbon losses occurred in England and Wales from 1978 to 2003 could possibly be attributable to climate warming.…”