This paper combines panel data from nationally representative household-level surveys in Nigeria with long-term satellite-based spatial data on temperature and precipitation using geo-referenced information related to households. It aims to quantify the impacts of climate change on agricultural productivity, income shares, crop mix, and input use decisions. We measure climate change in harmful degree days, growing degree days, and changes in precipitation using long-term (30 year) changes in temperature and precipitation anomalies during the crop calendars. We find that, controlling for other factors, a 15% (one standard deviation) increase in change in harmful degree days leads to a decrease in agricultural productivity of 5.22% on average. Similarly, precipitation change has resulted in a significant and negative impact on agricultural productivity. Our results further show that the change in harmful degree days decreases the income share from crops and nonfarm self-employment, while it increases the income share from livestock and wage employment. Examining possible transmission channels for this effect, we find that farmers change their crop mix and input use to respond to climate changes, for instance reducing fertilizer use and seed purchases as a response to increases in extreme heat. Based on our findings, we suggest policy interventions that incentivize adoption of climate-resilient agriculture, such as small-scale irrigation and livelihood diversification. We also propose targeted pro-poor interventions, such as low-cost financing options for improving smallholders' access to climate-proof agricultural inputs and technologies, and policy measures to reduce the inequality of access to livelihood capital such as land and other productive assets.

本文将尼日利亚具有全国代表性的家庭层面调查的面板数据与使用与家庭相关的地理参考信息的长期卫星温度和降水空间数据相结合。它旨在量化气候变化对农业生产力、收入份额、作物结构和投入物使用决策的影响。我们使用作物日历期间温度和降水异常的长期（30 年）变化来测量有害度日、生长度日和降水变化的气候变化。我们发现，在控制其他因素的情况下，有害度日变化增加 15%（一个标准差）会导致农业生产力平均下降 5.22%。相似地，降水变化对农业生产力产生了重大的负面影响。我们的结果进一步表明，有害度天数的变化降低了来自农作物和非农个体经营的收入份额，同时增加了来自畜牧业和有薪就业的收入份额。检查这种影响的可能传播渠道，我们发现农民改变他们的作物组合和投入使用以应对气候变化，例如减少化肥使用和种子购买以应对极端高温的增加。根据我们的发现，我们建议采取政策干预措施来激励采用气候适应型农业，例如小规模灌溉和生计多样化。我们还提出有针对性的扶贫干预措施，例如用于改善小农的低成本融资方案