Margaret Thatcher tendency to override collegiate opinion, contributed to discontent within her party. Thatcher removed Geoffrey Howe as Foreign Secretary in July 1989 after he and Lawson had forced her to agree to a plan for Britain to join the European Exchange Rate Mechanism (ERM). Britain joined the ERM in October 1990. On 1 November 1990, Howe, by then the last remaining member of Thatcher's original 1979 cabinet, resigned from his position as Deputy Prime Minister, ostensibly over her open hostility to moves towards European Monetary Union. In his resignation speech on 13 November, Howe commented on Thatcher's openly dismissive attitude to
Margaret Thatcher of the Hadley Centre for Climate Research and Prediction, the establishment of the Intergovernmental Panel on Climate Change, and the ratification of the Montreal Protocol on preserving the ozone. Thatcher helped to put climate change, acid rain and general pollution in the British mainstream in the late 1980s, calling for a global treaty on climate change in 1989. Her speeches included one to the Royal Society in 1988, followed by another to the UN General Assembly in 1989. However, after retiring as Prime Minister, she became sceptical about climate change policy and rejected climate alarmism. Thatcher appointed Lord Carrington, a