• Let’s be clear: the rate at which sunlight delivers energy to the Earth’s surface should be expressed in terawatts. Our “For the record” of 25 April (p 25) not only contained a nonsense of its own (suggesting that a terawatt is different from a terajoule per second), but also failed to address our original blooper, in which we referred to terawatts per day (4 April, p 24).
