Nicholas Lewis (Letters, 28 August) complained that your report (Arctic ice melt likely to break record, 24 August) gave the impression that typical temperatures in Antarctica have risen as much as on the Antarctic peninsula. While he is correct about this, his letter also refers to an outdated study of his, which argued that previous estimates of overall Antarctic warming were too high. In fact, the work of Lewis and co-authors has been proven wrong.
The relevant paper here is Orsi et al, Geophysical Research Letters, vol. 39, 2012, which shows that the rate of warming in west Antarctica is as great, or greater, than what we showed in our original work (Steig et al, Nature, vol. 457, 2009). Moreover, Lewis's own paper shows there has been significant warming in west Antarctica and that the average trend over Antarctica is of warming, not cooling as is often stated.
The reality is that the Antarctic is warming up and is contributing significantly to sea level rise; and that there is strong potential for a greater contribution to sea level rise from Antarctica in the future.
Professor Eric Steig
University of Washington, Seattle, USA
• Even as scientists report a record Arctic ice melt – indicating that man-made climate change is progressing at a faster pace than had been anticipated – the coalition continues to signal its readiness to spend taxpayers' money, no matter how harmful or ineffective (Heathrow runway row, 5 September). And it's not just Heathrow. Here in East Sussex the government and the county council are planning to spend over £100m on a three-mile road that will actually boost overall traffic levels, significantly increasing carbon emissions and destroying one of our area's greatest treasures, Combe Haven Valley. We believe thatwe can and must stop these environmentally devastating wastes of public money before it's too late.
Emily Johns
Charlotte Potter-Powell
Combe Haven Defenders
