Climate change's threats to Africa

Of all seven continents, Africa is believed to be most affected by climate change. Poverty, overfarming, overgrazing, deforestation, and increasingly erratic weather patterns all contribute to the conservative prediction that, if the world's temperature rises as little as two degrees by 2100, as many as 250 million Africans will be left without adequate drinking water. In Africa and Asia, the band along the tenth parallelis one of the most ecologically precarious in the world. Here, the inexorable southward spread of North Africa's desert, which occurs in Nigeria at an estimated rate of between a quarter and a half mile each year, meets unpredictable rains in the transition zone from Africa's dry north to its wet south.

Eliza Griswold, The Tenth Parallel: Dispatches from the Fault Line Between Christianity and Islam (New York: Farrar, Straus and Giroux, 2010), p. 39.

Alien earthworms contribute to America

In the forests of northeastern U.S. cities, leaves decompose quickly, much more quickly than they do in more natural settings. This might seem counterintuitive because city soils are disturbed, of low quality, and polluted. City trees also grow tough, decay-resistant leaves to fight water loss, pollution, and the mouths of herbivorous insects. Soil organisms, however, play a huge role in starting leaf breakdown, notably earthworms, which are more abundant in urban soils than in natural soils. The greater warmth of urban soils is favorable to earthworms and other agents of decay, but the greater abundance of worms in U.S. city soils also reflects their alien origins. Most earthworms are not native to the United States; they came from Europe as settlers brought in plants and horticultural soils from their native homelands.

Some of the most familiar invaders, such as "night crawlers" and "red wigglers," are clearly enhancing soil fertility and even helping stem climate change. . . . Carbon is also quickly stripped from the decaying plant matter by worms and stored in the soil. This may be the worm's greatest gift. Increasing the capacity of our soils to sequester carbon is a significant step that helps counter the carbon we release into the atmosphere.

John M. Marzluff, Welcome to Subirdia: Sharing Our Neighborhoods with Wrens, Robins, Woodpeckers, and Other Wildlife (New Haven: Yale Univ. Press, 2014), p. 167