The correct option is 1 and 3 only. The United Nations Convention to Combat Desertification (UNCCD) is crucial as it promotes national programs that facilitate effective actions against desertification, with a strong focus on integrating local community involvement in these efforts. This bottom-up approach ensures that local knowledge and practices are leveraged, which enhances the sustainability and effectiveness of initiatives aimed at combating land degradation and desertification, particularly in vulnerable regions. While it does address issues in South Asia and North Africa, its primary aim is broader, encompassing global strategies against desertification without specific focus on those regions.