Indeed, on several occasions during the last year he told me of two topics upon which he was working, concerning timescales far beyond our usual preoccupations with future climate policy. The first was a theory regarding how a geophysiological response of calcifying phytoplankton to changing oceanic CO2 might neatly explain the whole glacial-interglacial cycle, as he had demonstrated with a simple model. The second theory was on an even grander scale, concerning the mathematics of the topology of the universe. Recently he was so keen to explain these ideas that I could hardly persuade him to return to the topic of climate stabilisation, which was so remarkable for Jesper that it led me to guess, that he feared to have little time left even to write down what had been evolving in his head for many years.

So, I hope he has managed to write enough that somebody may continue to persue these ideas. If he left some gaps regarding the ocean calcification, I would be glad to try to help bridge these (as this topic is also related to that of my thesis). Normally it is hard to believe that somebody who had to devote most of his hours to issues such as loopholes in accounting for sinks or defending Danish wind-energy could on the side resolve conundrums of the universe, but Jesper was such a special exception that somebody should at least check it out.

Jesper had an exceptional mind, which could often jump to see connections more quickly than he could find a way to explain them. I observed on several occasions in IPCC meetings, that he would be the first to spot a key problem that needed to be fixed, but some iteration would be needed before others had worked out what he meant. Colleagues in the panel came to respect that if he insisted on some seemingly obscure point, there was probably a very good reason for it. Sometimes, perhaps frustrated by our slow response, he tried to explain with some amusing metaphors. I recall for example an FCCC workshop on sharing emissions quotas, in which he posed a long question about equity in terms of the price of lobsters (maybe this is a common analogy in Denmark?). Jesper was as passionately concerned about justice in climate policy as he was about honest science, whilst still patiently persuing this through the subtleties of negotiations.

It was also through metaphors that Jesper first explained to me his algorithm for resolving the simple carbon and climate models used by IPCC, which later became the core of my Java Climate Model, originally developed with him during 2000-1. To Jesper, originally trained as an electrical engineer, the essence of the UDEB model was just two capacitors (oceans) connected across the top by three resistors, which could be solved using prop/step/ramp functions (rather more efficiently than the original version). He also used electrical circuit analogies to consider feedback control problems, which intrigued us both, in part inspired by Lovelock's concept of geophysiology. On the other hand, when we explored applying “fuzzy control” to future climate policy, adjusting emissions in response to observations of how climate evolves, the result was not so encouraging: as he said, “it's like trying to steer a supertanker by eyesight through a rocky channel in the fog”.

Whilst Jesper's words about the climate policy process could sometimes seem pessimistic, his devotion to keep tackling this in diverse ways somehow suggested the opposite, and his ironic sense of humour helped to make our work seem lighter. I owe a special debt to Jesper because, much more than explaining the models, he gave me a new start in life at a time when we had both perceived the huge gulf between climate science and policy, but I had no practical pathway to help resolve it. Having spotted on the internet my initial experiments with a java model, whose concept was similar to his own web model allowing users to explore “how much do we have to bend the curve”, he invited me to Denmark in autumn 2000 to work with him and his colleague Prof Peter Laut at DTU, initially via a popular science project, another topic to which he devoted much effort. As well as providing the key foundation for development of the “Java Climate Model”, Jesper introduced me to other colleagues at the science policy interface, including Jean-Pascal vanYpersele here in Louvain la Neuve, with whom I now continue this work begun with Jesper.

As far as I recall, Jesper told me that his partnership with Peter Laut (which they called “DEA-CCAT”), and also his study of the IPCC models, had begun when he was asked to give a government response to defend these simple models from challenging critique by Peter, at that time an advisor to the coal industry. Jesper's dedication to work through the subtleties of all the equations persuaded Peter to respect, at least, the good intention behind these models, and they later formed a strong team working on many issues, for example writing several papers challenging the analyses of the Danish sceptics trying to assert that climate change was just a consequence of solar cycles and cosmic rays.

More recently, we met at workshops about the Brazilian proposal regarding contributions to climate change. I recall Gylvan Meira-Filho catching Jesper on the side of an IPCC plenary, as perhaps the only one who might quickly grasp his concept of matrices to calculate the cause-effect response for any vector of emissions. Jesper later developed into an elegant analysis presented at several meetings of ACCC/MATCH process, upon which I hope we may continue to build.

I emphasise this type of modeling work “on the side”, specifically because he persued such ideas not to gain recognition or to fulfil his governmental role, but modestly, driven by some inner compulsion, either for the planet, or just for curiosity. We both felt that the “system” is not enough, that we have to explore other ways. In the overly suspicious world of climate negotiations, maybe some people wondered what was the conspiracy between myself and Jesper - the answer could be precisely that there was none, that we could discuss any topic with no personal agenda, nor any clever word games, just quietly trying to understand what we can do.

Thus, although I only knew Jesper for a few years, I feel the loss of a very special friend. It is to me tragic but self-evident, that we have lost Jesper so early, because he cared so much for the health of the global atmosphere, that he sacrificed the health of the local atmosphere inside his own lungs. Working with him I observed how the smoke somehow seemed to give him the energy to keep going through the small hours of the morning solving models and equations. In essence, it could be said that he had borrowed time from his own future, in order that the world may have a little more time to solve the climate problem. So now we owe it to him to keep trying to bend that curve. Thankyou, Jesper, for much inspiration, and may your ideas persist over the long timescales about which you were thinking.