1 March 2017, The Conversation, As global food demand rises, climate change is hitting our staple crops. While increases in population and wealth will lift global demand for food by up to 70% by 2050, agriculture is already feeling the effects of climate change. This is expected to continue in coming decades. Scientists and farmers will need to act on multiple fronts to counter falling crop yields and feed more people. As with previous agricultural revolutions, we need a new set of plant characteristics to meet the challenge. When it comes to the staple crops – wheat, rice, maize, soybean, barley and sorghum – research has found changes in rainfall and temperature explain about 30% of the yearly variation in agricultural yields. All six crops responded negatively to increasing temperatures – most likely associated with increases in crop development rates and water stress. In particular, wheat, maize and barley show a negative response to increased temperatures. But, overall, rainfall trends had only minor effects on crop yields in these studies. Since 1950, average global temperatures have risen by roughly 0.13°C per decade. An even faster rate of roughly 0.2°C of warming per decade is expected over the next few decades. As temperatures rise, rainfall patterns change. Increased heat also leads to greater evaporation and surface drying, which further intensifies and prolongs droughts. A warmer atmosphere can also hold more water – about 7% more water vapour for every 1°C increase in temperature. This ultimately results in storms with more intense rainfall. A review of rainfall patterns shows changes in the amount of rainfall everywhere. Read More here
Category Archives: Food & Water Issues
14 February 2017, Think Progress, Sinking from drought, California is now also flooding. After weeks of rain, Northern California’s surface water systems have been pushed to the breaking point, even while the effects of a five-year drought continue to threaten the state’s long-term groundwater supplies. More than 180,000 people were evacuated Sunday afternoon after spillways for the Oroville Dam in Northern California showed signs of possible collapse. The potential flooding comes as California begins to emerge from its historic, drought. But despite the overabundance of water on the surface, drought conditions underground have likely had a permanent impact on the state. Even under the best conditions, it could take half a century for underground reservoirs to refill. Recent analysis from the California Institute of Technology shows that drought — combined with water use — has caused parts of California to sink, perhaps permanently. Some places show up to two feet of subsidence over the past two years. That’s because as surface water from rain and snowmelt has decreased, farmers have been using more groundwater from reservoirs. “Subsidence caused by groundwater pumping in the Central Valley has been a problem for decades,” write the authors of a new study, which uses NASA data to track California’s sinking. Pumping groundwater reduces the support below-ground aquifers give to the surface, causing it to sink. In recent years, that process has been sped up, as California’s drought has reduced the surface water available to farmers. While surface water can come in the form of rain, or snowmelt, groundwater sits in aquifers and is the result of a slow build up of water below ground. Read More here
26 December 2016, Climate News Network, Online calculator cuts farms’ emissions. An internet tool is now available that helps to quantify and control farms’ greenhouse emissions released during the crop production cycle. It’s called the Cool Farm Tool (CFT) – an easy-to-use online calculator that helps farmers monitor their emissions of greenhouse gases. Agriculture accounts for about 15% of total global greenhouse gas emissions, though when fertiliser manufacture and use and the overall food processing sector are included in calculations, that figure is considerably higher. The land can also act as a vital carbon sink, soaking up or sequestering vast amounts of carbon: when soils are disturbed the carbon is released, adding to greenhouse gases in the atmosphere. The CFT was initially developed by researchers at the University of Aberdeen in the UK in partnership with Unilever and the Sustainable Food Lab. Now managed by a group including academics and food manufacturers called the Cool Farm Alliance, the CFT is free for farmers to download. Various details, including the crops being planted, soil types and pH levels (the relative acidity or alkalinity of the land), are entered into a series of boxes. Moisture levels, amounts and types of fertiliser used and general management details are also entered, along with information on quantities of diesel and electricity used in the cultivation and storage of crops and the fuel needed to transport goods on and off the farm. Halving emissions In 2010 PepsiCo, the drinks and food conglomerate, launched a programme aimed at making its operations more environmentally friendly. In particular it sought to halve the amount of greenhouse gas emissions and water use arising from production at its Walkers Crisps factory at Leicester in the UK – the largest such plant in the world, producing five million packets of crisps (known as potato chips in the US) every day. A central part of the PepsiCo project involved encouraging its potato suppliers to farm more sustainably through the use of the CFT and by using other devices to monitor and cut back on water use. New potato varieties with improved yields were also introduced. Within six years, the goal of halving carbon emissions and achieving a 50% reduction in water use was reached. Read More here
21 December 2016, The Conversation, Why we can get over the ‘yuck factor’ when it comes to recycled water. In light of climate change and a growing population, water authorities around the world are looking at the treatment of recycled water to achieve water security and sustainability. Recent authors on The Conversation have raised the possibility of expanding the use of water recycling in Australia, noting the potential benefits for domestic, agricultural and industrial water supply. Some contributors have noted that the major roadblocks to water recycling, in places where it could be beneficial, are not technical issues, but public reluctance to use recycled water. Emotional Responses In the past, our aversion to recycled water has been explained by the “yuck factor”. Some people have an emotional response of disgust to using recycled water, even when they know it has been highly treated and is safe. There are large individual differences in the strength and type of different people’s disgust responses. Psychologists have tried to understand why our thought processes can lead some people to think of recycled water as unclean. One explanation is contagion thinking, the idea that once water has been defiled it will always remain unclean, regardless of treatment, at least according to the mental models that underlie our emotional responses. What such approaches often neglect is that cognition does not occur in a cultural vacuum, but is affected by the associations and stigmas of society. It is important to note that these emotional responses are often in conflict with our rational thinking. Some theorists, such as Nobel laureate Daniel Kahneman, have argued that we make judgements using two contrasting systems. One of these systems is slow and operates according to a formal risk calculus. The other is fast, based on positive or negative emotional responses. Because of this, how we feel about someone or something (positively or negatively) is often as important as what they are being judged on. In other words, the fact that a person understands that a highly treated sample of recycled water is safe to drink may not be enough to stop the emotional response, as we often tend to think intuitively, drawing on our social and cultural values. The most important question, however, is whether the emotional responses some people have to recycled water can be changed. And what role do stigmas associated with cultural norms play in shaping these? Read More here