We are pleased to see the three follow- up letters concerning our “World Scientists’ Warning to Humanity: A Second Notice” (Ripple et al. 2017). Each letter expresses a thoughtful, heartfelt response to our paper. We agree in how they describe the need to get more scientists into policymaking positions (Dror), to create a new global environmental ethic (Skubała), and to recognize economic growth as a major driver of environmental impacts (Pacheco et al.). The letters rais...
It is projected that 25 million km of new paved roads will be developed globally by 2050—enough to encircle the planet more than 600 times. Roughly 90% of new roads will be built in developing nations, frequently in tropical and subtropical regions with high biodiversity and environmental values. Many developing nations are borrowing from international lenders or negotiating access to their natural resources in order to expand their transportation infrastructure. Given the unprecedented...
Twenty-five years ago the Union of Concerned Scientists and more than 1,500 scientists, including the majority of living Nobel laureates in the sciences, penned the 1992 “Scientists’ Warning to Humanity.” These scientists called on humankind to curtail environmental destruction and cautioned “a great change in our stewardship of the Earth and the life on it is required, if vast human misery is to be avoided.” In their manifesto, they showed that humans are on a collision course with...
The tropical forests of Africa are experiencing unprecedented changes as a result of a rapid proliferation of roads and other infrastructure. These projects are dramatically increasing access to relatively unexploited regions, particularly in the greater Congo Basin. We highlight some of the most important new projects and describe in detail an ongoing debate about a particular proposed development, the Cross River Superhighway in Nigeria. The scale and pace of new transportation projects, an...
This study analyzed the spatiotemporal pattern of settlement expansion in Abuja, Nigeria, one ofWest Africa’s fastest developing cities, using geoinformation and ancillary datasets. Three epochs of Land-use Land-cover (LULC) maps for 1986, 2001 and 2014 were derived from Landsat images using support vector machines (SVM). Accuracy assessment (AA) of the LULC maps based on the pixel count resulted in overall accuracy of 82%, 92% and 92%, while the AA derived from the error adjusted area (EAA...
The Cross River State Government in Nigeria is proposing to construct a ‘‘Cross River Superhighway’’ that would bisectcritical remaining areas of tropical rainforest in south eastern Nigeria. We offer and evaluate two alternative routes to the superhighway that would be less damaging to forests, protected areas, and biological diversity. The first alternative we identified avoids intact forests entirely while seeking to benefit agriculture and existing settlements. The second altern...
Mahmoud Ibrahim Mahmoud is currently a postdoctoral research fellow (computer geospatial modeller) with the Centre for Tropical Environmental and Sustainability Science (TESS) James Cook Univ
