Although 79% of carbon emissions is produced by developed countries, and developing countries have not been the major cause of climate change, they are the most at risk from the effects of these changes and may face challenges in adapting to climate change due to the intersecting issues of high climate vulnerability, low economic status, restricted access to technology, failing infrastructure and limited access to financial resources. Where a country is particularly vulnerable to climate change they are called "highly climate vulnerable". This applies to many countries in Sub-Saharan Africa, fragile states or failed states like Afghanistan, Haiti, Myanmar, and Somalia, as well as to Small Island Developing States. In the cases where developing countries produce only small quantities of greenhouse gas emissions per capita but are very vulnerable to the negative effects of global warming, the term "forced riders" as opposed to the "free riders" has been used as a descriptor. Such countries include Comoros, The Gambia, Guinea-Bissau, São Tomé and Príncipe, Solomon Islands and Vanuatu.