A new United Nations scientific report says that human-caused climate change is greatly reducing land quality worldwide. It also warns that the way humans use land is causing the Earth’s atmosphere to warm faster and could harm food production. The Intergovernmental Panel on Climate Change published its latest report on Thursday. It examines the relationship between climate change and land use, agriculture and food security. The report notes that the effects of climate change are already making food more costly and less nutritious, and are worsening food shortages.