The Royal Geographical Society is housed in a red-brick building just south of Hyde Park, at a junction of Kensington Gore and Exhibition Road that London cab drivers call “hot and cold corner”. Its façades are decorated, respectively, with statues of the most famous explorer of Africa, David Livingstone, and the polar explorer Ernest Shackleton, hero of perhaps the greatest survival story of all time.

In 1998 when I was 27 and had just left the Financial Times after two years in the Philippines I was planning an ambitious 1,200-mile exploration by camel across the old slave routes of the little-travelled Libyan Sahara. Among my first ports of call was the RGS. I wanted to consult its unrivalled store of maps and charts of the world’s least hospitable places. Inside, it fairly hummed with potential expeditions, a stopping-off point for people about to set off to the remotest parts of the world. The walls of the society’s wonderful auditorium carry the names of great RGS-backed explorers of the past, including Sir Richard Burton, the great Victorian who, with John Speke, made two journeys into central Africa to locate the source of the Nile. And, of course, Captain Robert Falcon Scott, whose second expedition to the South Pole in 1912 ended in his death. Through their often heroic efforts the society advanced our understanding of the world.

On that first day I was there to study in the fusty grandeur of the panelled Map Room. I would politely ask the supervisor for what I needed and he would disappear, locate each map of the interminable desert wastes, and bring it to my desk. He might, I thought, have been there since Scott of the Antarctic set off across other, icier, wastelands.

Originally founded as a gentlemen’s dining club in 1830, within 30 years the RGS had established itself as the heart of what is now often described as the “heroic” age of expedition. As I explained what I was planning in Libya, an expedition to the historical centres of the Saharan slave trade, the RGS’s in-house expedition advisory centre put me in touch with some of the most notable desert explorers. They included Sir Wilfred Thesiger, then 88, and the charming octogenarian Rupert Harding-Newman, veteran of the Long Range Desert Group in the second world war. The latter was invaluable in helping me to learn the essentials of desert navigation.

Without this first encounter with the RGS, my Libyan journey (which I later wrote about in my first book, South From Barbary) might never have happened and I would probably never have become a fellow of the society. There are 10,500 fellows, all of whom have been nominated and approved for fellowship, and then have the right to vote on RGS resolutions.

That year – 1998 – was the last time that the Royal Geographical Society (with the Institute of British Geographers, to give it its full title) organised, paid for, and launched one of its own expeditions, an extensive study of the marine environment in the south-west Indian Ocean, involving 200 scientists from 21 countries. The team generated huge quantities of scientific data and trained hundreds of local officials in marine education and management. Since 1998, the RGS has given money to many expeditions, but it hasn’t launched a major expedition in its own right.

Perhaps this is unsurprising. By 1998 the age of heroic exploration was long over – possibly the last great “expedition” was the RGS-assisted trans-Arctic expedition of 1967-69, described by then British prime minister Harold Wilson “as a feat of endurance and courage which ranks with any in polar history”. Three men and 40 dogs, carrying 32 tonnes of food and equipment, took more than 15 months to cross 3,800 miles of frozen wilderness. It was the longest sustained polar journey in history and almost certainly the first surface crossing of the Arctic Ocean.

The Earth has now been almost entirely charted (though we know little about its oceans). Yet there is still a world to be discovered by teams of geographers and scientists working together to improve our understanding of the fragile balance of life on our planet. As the distinguished environmental scientist James Lovelock laments in his book The Vanishing Face of Gaia: A Final Warning: “Observation in the real world and small-scale experiments on the Earth now take second place to expensive and ever-expanding theoretical models” of questionable reliability. “Our tank is near empty of data and we are running on theoretical vapour,” he argues. There is a compelling need for “more tiresome and prosaic confirmation by experiment and observation”.

The RGS has a record of mounting data-collecting expeditions of world-class importance. In 1987, for example, John Hemming, then its director, led a 200-strong expedition to the Maracá rain forest project in Brazilian Amazonia. At the invitation of the Brazilian government and in collaboration with the National Amazon Research Institute, researchers surveyed the rich forests of the riverine island of Maracá, together with four related programmes on forest regeneration, soils and hydrology, medical entomology and land development. The success of the project led to an accord between British and Brazilian scientists for long-term research in Amazonia. It represents, I believe, the RGS at its finest.

Yet the past decade has seen the society shift its focus towards academic geography, and away from exploration and field research. In 2006, for instance, the expedition advisory centre was re-branded “geography outdoors”. It was a move widely seen by fellows as a downgrading of expeditions and exploration within the society. It was, said the veteran explorer Robin Hanbury-Tenison, when I interviewed him for a newspaper, “mealy-mouthed”.

In May 2006 Alistair Carr, a Suffolk-based travel writer and desert explorer, went to the RGS archives and called up a copy of the society’s original, hand-written Royal Charter. He was looking for something that might back his hunch that the direction of the RGS had, in recent years, veered too far from exploration. Poring over the hard-to-read text, he found this: “The Royal Geographical Society, for the advancement of Geographical Science … has since its establishment sedulously pursued such its proposed object … by carrying out, at its own expense, various important Expeditions in every quarter of the Globe, and by assisting other Expeditions with grants of money and otherwise … ”

Carr realised that this could be a chance to change things. “I started talking to people all over the country – scientists, zoologists, entomologists, marine biologists, the British Antarctic Survey, the Natural History Museum and so on,” he says. “The more I spoke to these people, the more I realised there was this crying need for these multidisciplinary expeditions and that the society was losing this wonderful opportunity. With all those unknowns out there, in the oceans, rainforests, mountains and deserts, there’s so much more to be done. I felt the RGS should be leading the way.”

Over the next few months, he assembled a group of six like-minded RGS fellows, including myself, all in their thirties. Carr already knew Tim Bosworth, an environmental scientist, and the others were all keen to meet – so in April 2007 Carr, Bosworth, and I met up in London with Jo Vestey, an award-winning photographer, explorer and broadcaster Oliver Steeds and James Aldred, a rainforest veteran and specialist wildlife cameraman.

Over the past two years, we have exchanged numerous letters with the RGS leadership. We have sat down with the director and president and members of its council. Our request was that the RGS should return to launching its own multi-disciplinary scientific research projects and expeditions. The RGS itself says that over the past four years it has supported more than 250 projects involving 1,250 people in 118 countries with more than £600,000 in funding.

Our small group talked and the RGS listened. But, while we believe the society’s recent emphasis on geography and education is commendable, we feel that this must not come at the expense of its important core activity – running its own expeditions. So this month, our campaign, which we are calling the Beagle Campaign in honour of Charles Darwin’s 1831-1836 expedition – assisted by the RGS – to South America, went public.

Two days ago, a parcel was delivered to Lowther Lodge, the society’s home. It contained a special resolution, instigated by Carr and his five original signatories, calling for a return to the society’s own expeditions. The resolution calls on the RGS to honour its obligations as set out in its Royal Charter of 1859: in a word, to explore.

For a special resolution to be taken to a vote by the RGS, it has to be signed by six fellows and supported by at least 40 more. Our resolution has been co-signed by 80 of the most distinguished figures in the fields of exploration, geography, science, literature and travel. They include Sir Ranulph Fiennes; George Band, who was at 23 the youngest climber to scale Everest for the first time in 1953, along with his equally distinguished successors Sir Chris Bonington and Doug Scott; and the modern polar explorers Pen Hadow, who is currently in the Arctic, and Tom Avery, the youngest Briton to reach both poles.

Other supporters include Ian Swingland, a world expert on conservation and biodiversity, Andrew Mitchell, an authority on forest canopies and climate change, anthropologist Dr Audrey Colson and cave specialist Andrew Eavis.

The next step for the RGS would be to call a special general meeting and send out ballots to its 10,500 fellows. The wording of our resolution modifies its charter’s requirement for the RGS to fund expeditions “at its own expense”. It calls, instead, for a return to sponsored expeditions. (Major RGS expeditions from 1977-1998 include an impressive list of corporate backers: Shell, Cathay Pacific, British Airways, Wimpey, Honda, Land Rover.)

In response to receiving the resolution this week, the society’s initial statement said: “The RGS-IBG would like to make it clear that the society’s objective, as set out in the royal charter of 1859, is the ‘advancement of geographical science’. The ways in which the society does this is a matter for the trustees at any particular time. The society continues to support exploration constantly.”

If it’s no longer mountain summits or poles we seek, so much as greater knowledge about climate change, growing urban populations, poor water supply, forced migrations and a host of other unknowns, our knowledge of species on the planet still has an enormous way to go. Marine biologists estimate that there may be up to 50m new species within the largely unexplored oceans, and up to 10m new species of insects, many of them in the world’s endangered tropical rainforests.

For a model of the sort of expedition that we hope will once again set out from South Kensington, look at Hadow’s latest Arctic expedition, an international venture funded by sponsors, including the insurance group Catlin, and bringing science and exploration together in an effort to answer one of the most critical environmental questions of our time: how long will the Arctic Ocean’s sea ice cover remain a permanent feature of our planet?

In 1980, the RGS celebrated its 150th anniversary with the publication of To the Farthest Ends of the Earth, a history of the society by Ian Cameron. In a foreword, RGS fellow Sir David Attenborough said the next 150 years would witness different sorts of RGS expeditions, “But the stimulus that sends its members on arduous journeys to remote places will surely remain the same; and the society, thankfully, will continue to serve them.”

The Beagle Campaign offers thousands of fellows and members – together with the public – the chance to make our voices heard. We welcome all support from anyone interested in this cause. If successful it will help ensure that the society, in addition to supporting research projects, starts to field its own major expeditions once again. The future of the planet deserves nothing less.

www.thebeaglecampaign.com