IPCC Climate Change Data: CGCM1 A2a Model: 2020 Mean Temperature

From the IPCC website: For the A2 emissions scenario the main emphasis is on a strengthening of regional and local culture, with a return to family values in many regions. The A2 world consolidates into a series of roughly continental economic regions, emphasizing local cultural roots. In some regions, increased religious participation leads many to reject a materialist path and to focus attention on contributing to the local community. Elsewhere, the trend is towards increased investment in education and science and growth in economic productivity. Social and political structures diversify, with some regions moving towards stronger welfare systems and reduced income inequality, while others move towards "lean" government. Environmental concerns are relatively weak, although some attention is paid to bringing local pollution under control and maintaining local environmental amenities. The A2 world sees more international tensions and less cooperation than in A1 or B1. People, ideas and capital are less mobile so that technology diffuses slowly. International disparities in productivity, and hence income per capita, are maintained or increased. With the emphasis on family and community life, fertility rates decline only slowly, although they vary among regions. Hence, this scenario family has high population growth (to 15 billion by 2100) with comparatively low incomes per capita relative to the A1 and B1 worlds, at US$7,200 in 2050 and US$16,000 in 2100.Technological change is rapid in some regions and slow in others as industry adjusts to local resource endowments, culture, and education levels. Regions with abundant energy and mineral resources evolve more resource intensive economies, while those poor in resources place very high priority on minimizing import dependence through technological innovation to improve resource efficiency and make use of substitute inputs. The fuel mix in different regions is determined primarily by resource availability. And divisions among regions persist in terms of their mix of technologies, with high-income but resource-poor regions shifting toward advanced post fossil technologies (renewables in regions of large land availability, nuclear in densely populated, resource poor regions) and low-income resource-rich regions generally relying on older fossil technologies.With substantial food requirements, agricultural productivity is one of the main focus areas for innovation and RD efforts in this future. Initially high levels of soil erosion and water pollution are eventually eased through the local development of more sustainable high-yield agriculture.Although attention is given to potential local and regional environmental damage, it is not uniform across regions. For example, sulfur and particulate emissions are reduced in Asia due to impacts on human health and agricultural production but increase in Africa as a result of the intensified exploitation of coal and other mineral resources. The A2 world sees high energy and carbon intensity, and correspondingly high GHG emissions. Its CO2 emissions are the highest of all four scenario families. Data are available for the following periods: 1961-1990, 2010-2039; 2040-2069; and 2090-2099 Mean monthly and change fields.

本数据集内容源自政府间气候变化专门委员会（IPCC，Intergovernmental Panel on Climate Change）官网。针对A2排放情景，其核心导向为强化区域与本土文化，诸多地区回归家庭价值观。A2情景下的世界将整合为若干大致以大陆为单元的经济区域，凸显本土文化根基。部分地区因宗教参与度提升，诸多民众摒弃物质主义发展路径，转而专注于回馈本地社区；其他地区则呈现出加大教育与科技投入、提升经济生产率的趋势。

社会与政治结构呈现多元化特征：部分地区构建起更为完善的福利体系，收入不平等程度有所降低，而另有部分地区转向“精简型”政府治理模式。环境议题受重视程度相对有限，不过部分地区会着力管控本地污染、维护本土环境宜居性。相较于A1与B1情景，A2情景下的世界国际紧张局势更多、国际合作更少。人员、思想与资本流动性偏弱，技术扩散进程缓慢。生产率进而人均收入的国际差距得以维持甚至进一步扩大。由于情景侧重家庭与社区生活，生育率仅缓慢下降，且地区间存在差异。因此该情景家族的人口增长规模较高（至2100年达150亿），相较A1与B1情景人均收入水平偏低：2050年为7200美元，2100年为16000美元。

部分地区技术变革快速，部分地区则进展缓慢，这是由于产业需适配本地资源禀赋、文化与教育水平。能源与矿产资源丰富的地区会发展资源密集型经济，而资源匮乏地区则将通过技术创新提升资源利用效率、开发替代投入品，以此作为降低进口依赖度的核心要务。各地区的燃料结构主要由资源可得性决定。地区间的技术结构分化持续存在：高收入但资源匮乏的地区正转向先进的后化石能源技术（土地充裕地区发展可再生能源，人口稠密、资源匮乏地区发展核电），而低收入且资源富集的地区总体上仍依赖传统化石能源技术。

由于粮食需求庞大，农业生产率是该未来图景下研发（R&D，Research and Development）与创新的核心重点领域之一。初期严重的土壤侵蚀与水污染问题，最终将通过本地发展可持续高产农业得到缓解。

尽管会关注潜在的本地与区域环境损害，但该情况在各地区并不均衡。例如，亚洲地区因二氧化硫与颗粒物排放对人体健康及农业生产造成影响，故而降低了此类排放；而非洲地区则因加大煤炭与其他矿产资源开发力度，导致相关排放有所增加。A2情景下的世界能源强度与碳强度均处于较高水平，相应的温室气体（GHG，Greenhouse Gas）排放量也较高，其二氧化碳（CO₂）排放量为四类情景家族中最高。

可用数据涵盖以下时段：1961-1990年、2010-2039年、2040-2069年以及2090-2099年，包含月均均值与变化量字段。