It is July 9, 2113. The mean global temperature has increased by 4 degrees Celsius above pre-industrial levels. Reason? One hundred years ago world leaders failed to pay attention to urgent warnings to curb emissions of heat-trapping carbon dioxide. The concentration of carbon dioxide today is 800 parts per million, compared to 400 parts per million in 2013.
Yesterday, July 8, 2113, the United Nations declared that global food reserves are dangerously low. Marine fisheries have crushed; agriculture in sub-Saharan Africa has collapsed under prolonged drought, pests, heat stress and flooding. Vector-borne diseases chronically debilitate billions of people. Billions of people are pouring across national borders, displaced by extreme weather. Billions more are hungry and infirm. East Africa’s savannah based tourism has collapsed because high carbon dioxide fertilization favored a shift from grassland to woodland. The Islands of Pemba and Zanzibar have recently disappeared, including the booming economies of Mombasa and Dar es Salaam.
A new report, Turn Down the Heat: Climate Extremes, Regional Impacts, and the Case for Resilience, prepared for the World Bank by the Potsdam Institute of Climate Research and Climate Analytics reveals that mean global temperatures could increase by 2 degrees Celsius in the next 20 to 30 years. As a consequence, the likelihood of 4 degree Celsius warming being reached by 2100 has increased.
In sub-Saharan Africa, climate-related extreme events could reverse economic and social progress, pushing hundreds of millions below the poverty line. High temperatures and moisture stress will affect food security adversely. The report reveals that by 2030, 40% of current maize cropping will no longer be suitable for today’s varieties. There are indications that yields could decrease by 15-20% across all crops.
The report reveals that there is a high likelihood of high intensity rainfall periods in the Horn of Africa and parts of East Africa, which is likely to, increase the risk of flooding. Overall, higher drought intensity is projected for the Great Horn of Africa. The 2011 drought in the Horn of Africa, which was particularly severe in Kenya and Somalia, is consistent with an increased probability of long-rains failure under a warming planet. Moreover, increased atmospheric concentrations of carbon dioxide is likely to accelerate a shift from grass to woodland savanna, with a likely negative impact on pastoral livelihoods and economies if pasture–based resources are reduced.
The connection between extreme weather and decline in GDP has been established. For example Kenya suffered annual damages of 10-16% of GDP because of flooding associated with the El Nino in 1997-98 and the La Nina drought of 1998-2000. It has been shown that both rainfall and temperature have contributed significantly to poor economic growth in sub-Saharan Africa. Recent studies have shown that a 1% increase in the spatial area of a sub-Saharan Africa experiencing moderate drought correlates with a 2-4% decrease in GDP growth.
The increasing fragility of natural and managed ecosystems and their services is in turn expected to diminish the resilience of sub-Saharan Africa’s socioeconomic systems, leaving them more vulnerable to non climatic stressors and shocks, such as emerging pandemics, trade disruptions, or financial market shocks. Climate change is a fundamental threat to economic development and the fight against hunger, poverty and disease, especially in sub-Saharan Africa. A warmer planet will exacerbate undernourishment, stunting, undermine educational performance and cause morbidity and mortality from malaria and other diseases to rise in just a few decades.
A report by the United States National Climate Assessment released early this year admits that the consequences of human induced climate change are now hitting the country on several fronts including health, infrastructure, water supply, agriculture and especially more frequent severe weather such as Superstorm Sandy.
Our science has brought unequivocal clarity to present and future global climate change. Climate change can no longer be seen as some future risk, a canister that can be kicked down the hill. Urgent action to cut down greenhouse gas emissions is needed now. As a global citizens, individuals, communities and governments we must respond urgently to curb greenhouse gas emissions and respond robustly to help our civilization adapt to the unfolding impacts triggered by past emissions.
All too frequently, inaction is motivated by the perceived high economic cost of cutting greenhouse gas emissions. But the cost of inaction or the tranquilizing drug of gradualism will be incalculable; the collapse of our civilization as we know it today.