• Polar species and societies have developed very specialized adaptations to the harsh conditions found at the poles, thus they are extremely vulnerable to dramatic changes in these conditions. • Low resilience to changing environmental parameters, including fluctuations of air temperatures and precipitation dynamics.
• About 7,000 plant species have been cultivated for food since agriculture began about 12,000 years ago. Today, however, only about 15 plant species and eight animal species supply 90% of our food. Many traits incorporated into these modern crop varieties were introduced from wild relatives. Unfortunately, many wild races of staple food crops are endangered. For example, one quarter of all wild potato species are predicted to die out within 50 years, which could make it difficult for future plant breeders to ensure that commercial varieties can cope with a changing climate. Climate change may affect plant growth and production by • Promoting the spread of pests and diseases. • Increased exposure to heat stress, • Changes in rainfall patterns, • Greater leaching of nutrients from the soil during intense rains, • Greater erosion due to stronger winds, and • More wildfires in drier regions .
Drylands are particularly vulnerable to climate change because: • Small changes in temperature and rainfall patterns can have serious impacts on the biodiversity of dry and sub-humid lands. • Drylands are already under stress from various activities, including conversion to agriculture, the introduction of invasive species, alterations to fire regimes, and pollution. • The impacts of climate change on drylands may have significant repercussions on populations and economies. Many people are highly dependent on drylands biodiversity. For example, about 70% of Africans depend directly on dry and subhumid lands for their daily livelihoods. • Deserts are projected to become hotter and drier. Higher temperatures could threaten organisms that are already near their heat-tolerance limits. Example, CC is likely to have serious impacts on the Succulent Karoo, the world’s richest arid hotspot, located in the southwestern part of South Africa and southern Namibia.