Some agricultural practices cause erosion, which results in increasingly poorer crop yields. As industrial agriculture intensifies, soils become degraded, and we have been losing millions of acres of productive cropland each year. Soil degradation is the major component of land degradation globally, and desertification affects large areas in the world's arid regions. Farming techniques such as crop rotation, contour farming, intercropping, terracing, shelterbelts, and conservation tillage help to reduce soil erosion and boost crop yields. Overgrazing can degrade soil and affect native ecosystems, but herd rotation, grazing limits, and cooperation with scientists researching grazing techniques and impacts can all contribute to more sustainable grazing. Both mitigation and adaptation are necessary. We can reduce greenhouse gas emissions with multiple strategies, including conservation, energy efficiency, clean and renewable energy sources, new automotive technologies, and investment in mass transit. International efforts to design effective treaties to restrain climate change have, so far, fallen short of what is needed. However, renewable energy technologies present economic opportunities, and some states, cities, and businesses are acting to address emissions. Carbon trading and carbon taxation offer promising ways to harness market forces and financial incentives to help reduce emissions. In various ways, coal mining, oil and gas drilling, and oil sands extraction can alter ecosystems, pollute air and waterways, and pose health risks. Hydraulic fracturing magnifies some of these impacts. Fuels can also spill during transport, affecting soil, water, wildlife, and health. Emissions from fossil fuel combustion pollute air, pose human health risks, and drive global climate change. Public policy and advances in pollution control technology have reduced many of these emissions, but much more remains to be done. If we could safely capture carbon dioxide and sequester it underground, this would resolve a primary drawback of fossil fuels, but carbon capture and storage remains unproven so far.