The world’s leading climate scientists have issued their most extensive warning yet on the risks associated with increasing global temperatures. The authors of the new report, published yesterday in Incheon, South Korea, by the Intergovernmental Panel on Climate Change (IPCC), say that urgent, far-reaching and unprecedented actions are needed across society, in order to limit warming to a maximum of 1.5°C above pre-industrial levels. Exceeding this target by even half a degree significantly increases the risk of flooding, droughts, extreme heat and poverty for millions of people around the world. However, the authors believe the changes needed are achievable, but only if we act now.
“Caring for the Planet from the Ground” is the theme of this year’s World Soil Day (#worldsoilday). World Soil Day (WSD) is an annual campaign aimed at raising awareness of the critical importance of healthy soils and advocating for the sustainable management of global soil resources. In June 2013, the FAO Conference endorsed WSD and requested for it to be officially adopted at the 68th UN General Assembly. As a result, 5 December 2014 was designated as the first official WSD. So why is soil so important and why should we care about the health of it?
Much attention has focused on what plants will be able to grow where as the effects of climate change are felt. A key factor that plays into that analysis is what effect climate change will have on diseases and weeds.Two new papers in CAB Reviews look at those two elements and show that that the picture is a complex and sometimes surprising one.
Sukumar Chakraborty (from CSIRO Plant Industry) and co-authors note that modelling experiments suggest that the range of key pathogenic fungi may shift significantly towards the poles as a result of global warming. The impacts of raised CO2 and temperature together are more difficult to estimate, as raised CO2 may increase the vigour of some trees and crops. From certain studies it seems that C3 plants, such as cereals, may suffer from increased numbers of pathogens with increased CO2, while C4 plants (most other crops and trees) may not. Chakraborty and colleagues write that minor changes in climate can tip the balance in favour of an exotic species, and the same may be true of disease outbreaks. Import risk analysis will need to take into account changes in the risks of establishment of pests and pathogens as the climate alters.
Examining the 12 most serious weeds, Xianshong Wang (from Indiana University-Purdue University Indianapolis) and Jacqueline Mohan (from the University of Georgia) suggest the competitiveness of weeds at higher temperatures and CO2 levels may be affected greatly by water availability. Most of the weeds will be expected to be boosted by rising temperatures. Field bindweed may become a more serious weed in drier regions, while it may be outcompeted in well-watered soils. Purple nutsedge may suffer because of expected reductions in moisture and rising soil nitrogen.
Wang and Mohan point out that the move to biofuels may exacerbate some of the projected weed problems: “Altered land use and the unforeseen consequences of energy plants may have a greater impact on the seriousness and injuriousness of weeds and weed-crop interactions than the effects of other global environmental changes, including rising CO2, global warming and more frequent and severe droughts.”
Effects of global environmental changes on weeds by Xianzhong Wang, J.E .Mohan
CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources, 2008, 3, No. 067, 20 pp.
Impacts of global change on diseases of agricultural crops and forest trees by S. Chakraborty, J .Luck, G. Hollaway, A. Freeman, R. Norton, K.A. Garrett, K. Percy, A. Hopkins, C. Davis, D.F. Karnosky
CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources, 2008, 3, No. 054, 15 pp.
We’ve explored obesity in many different forms during the course of this year
and if you’re a regular Handpicked reader (enter your email in the box on the
left and click on ‘subscribe’ to become one if you’re not already), you’ll by
now be well aware of a recurring theme in our nutrition posts. Energy. This
thread will doubtless also run through the imminent new CABI product
Environmental Impact (plug, plug), where I hope the loose ends help the experts
tie the information in nice, concise and user-friendly packages as opposed to a
confused mess of knots.