Rouse was born in Wallasey and began climbing at the age of 15, soon climbing many of the most difficult routes in North Wales. He attended Birkenhead School from 1963 to 1970 and Emmanuel College, Cambridge until 1973. At Cambridge he was distracted from his studies by climbing and by his hedonistic life-style. He was a highly sociable, but heavy drinker; by his own admission he was a 'womaniser', and liked to 'live on the edge'. As a result he only managed to gain an ordinary pass degree in Mathematics, despite showing early promise in the subject. On leaving Cambridge he worked periodically in teaching but was often away on climbing expeditions.
Rouse was an outstanding technical rock climber, one of the best of his generation. His ascents of 'The Beatnik' on Helsby, and his solo ascent of 'The Boldest' on Clogwyn Du'r Arddu marked him out as an exceptional talent. He was a member of a group of contemporaries (including Cliff Phillips, Eric Jones, Pete Minks, 'Richard' McHardy) whose competitive spirit pushed them the solo the hardest routes of the day.
His soloing was not confined to Wales, nor was it always successful. An attempt on the Brown route on the West Face of the Aiguille de Blatiere failed when a small piton being used for aid pulled near the summit. Although he fell only 5 meters, Rouse broke his ankle and was forced to abseil down the entire route, for much of the time using only his knees.
Rouse eventually became a professional mountaineer, lecturing, guiding, writing and acting as an adviser to the outdoor equipment trade. He moved to Sheffield in easy reach of the rocks of the Peak District. Rouse became a highly experienced climber in places as far afield as Scotland, North Wales, Patagonia, Peru, the Alps, the Andes, New Zealand and Nepal. He was also elected vice-president of the British Mountaineering Council.
In 1980, Rouse, Dr Michael Ward and Chris Bonington were among the few Europeans to visit the high mountains of China, reopening some of these to foreign mountaineers. In the winter of 1980—81, Rouse led a British expedition to attempt Mount Everest by the west ridge, without using oxygen or Sherpas. The trip was not successful, but in the summer of 1981 he climbed Kongur Tagh, a hitherto unclimbed peak in western China, with Bonington, Joe Tasker and Peter Boardman.
K2 is regarded as a much more difficult climb than Mount Everest and has a high fatality rate. In 1983, Rouse made his first attempt on K2 with an international team by a new route up the south ridge. In 1986, Rouse returned as the leader of a British expedition and obtained a permit to climb the difficult North-West Ridge, instead of the conventional Abruzzi ridge. After they had made several unsuccessful attempts to establish camps on their chosen route, the British team members — apart from Rouse and Jim Curran, a cameraman — left.
While Rouse and the British expedition attempted the North-West Ridge, other expeditions had also been trying various routes, with and without oxygen. After his fellow team members left the mountain, Rouse and six climbers from these expeditions decided to join forces to try the conventional route without a permit. There were four Austrian men, Alfred Imitzer, Hannes Wieser, Willi Bauer and Kurt Diemberger, a Polish woman, Dobroslawa Miodowicz-Wolf, and a British woman, Julie Tullis.
They reached Camp IV at (8,157 metres, 26,760 feet), the final staging post before the summit. For reasons that are still unclear, this impromptu team decided to wait a day before trying the final stage to the summit. None of the climbers on the Abruzzi Ridge chose to follow the team consisting of three Korean climbers who had set out on an oxygen aided attempt on August 3rd, even though the trail would have been broken through the deep snow for those climbing without oxygen. On the following day, it was obvious that the weather was deteriorating, but Rouse and Wolf set out for the summit. Wolf quickly tired and dropped back, whilst Rouse continued. Because he was breaking the trail alone, two of the Austrian climbers, Willi Bauer and Alfred Imitzer, caught up with him some 100 vertical meters below the summit. By then Rouse could fall in behind the Austrians, thus making his ascent easier the last stretch, and the three reached the summit together on August 4, 1986.
On the way down, they found Wolf asleep in the snow and persuaded her to descend. They also met Kurt Diemberger and Julie Tullis, still on their way up and tried to persuade them to descend but with no success. Diemberger and Tullis also summitted but very late, at dusk which occurred around 7 pm. On the descent, Tullis fell. Even though she survived, both Tullis and Diemberger had to spend the night, bivouacked in the open.
Eventually, all the climbers reached Camp IV, where Hannes Wieser, waited. The seven waited for the storm to abate. Instead, the storm worsened with much snow, winds over 160 km/h, and sub-zero temperatures. With no food or any gas to melt snow into water, the situation soon became life threatening. Tullis died during the night of August 6—August 7, presumably of HAPE, high altitude pulmonary edema, a common consequence of lack of oxygen during physical exertion. The other six climbers stayed for the next three days, but remained barely conscious. On August 10, the snow stopped, but the temperature dropped and the wind continued unabated. The climbers, although severely weakened, decided that they had no option but to move.
Rouse, when conscious, was in agony, and the other climbers decided to leave him to save their own lives. Of the seven climbers who had originally reached Camp IV on August 4 and August 5, only Diemberger and Bauer reached Base Camp.
Alan Rouse is presumed to have died on August 10, 1986. He was survived by his girlfriend, Deborah Sweeney, who gave birth to their daughter, Holly, three weeks later.