have acted simultaneously or in succession and it is not possible to determine which person's act caused the damage. A similar provision is to be found in the Austrian Civil Code: 1302 In such a case, if the injury is inadvertent, and it is possible to determine the portions thereof, each person is responsible only for the injuries caused by his mistake. If, however, the injury was intentional, or if the portions of the individuals in the injury cannot be determined, all are liable for one and one for all; however, the individual who has paid damages is granted the right to claim reimbursement from the others. In a Norwegian case (see Nils Nygaard, Injury/Damage and Responsibility, 2000, pp 342-343) F was a passenger on a motor scooter and was injured in an accident caused either by a cable stretched across the street by a construction company or by the motor scooter falling onto him or as a result of collision with a truck, or by any combination of these factors. In giving judgment (RG 1969 p 285 at 293) the Norwegian court said: As stated in the beforementioned conclusions made by experts, they could not conclude whether the situation that resulted in crushed bones in F's left hip region, was a result of falling on the cobble stones in the street or from the truck's front tyre, that ended up on top of F's left hip region. It is possible that the injuries were partially a result of the fall and being hit by the truck. We cannot say anything definite about this. The court finds that it cannot conclude whether it is the fall or being hit by the truck or a combination of both these factors that caused the injury. After a collective evaluation of the whole event the court finds that A (construction company), the scooter and the truck each have a part in F getting injured and each of them must naturally be seen as adequate cause of injury. UK asbestos / mesothelioma cases Of particular interest is a line of cases from the UK relating to asbestos exposure and the development of the cancer mesothelioma. The cases contain a number of features likely to arise in the context of climate change litigation such as: • slow onset • uncertainty regarding precise causal chain between conduct and harm • exposure from diverse sources. However it is important to note that these cases concern a difficulty not arising in the context of climate change litigation. Mesothelioma, much like malaria, is understood to be caused by a single exposure rather than by cumulative effect. Consequently where a number of defendants have exposed the claimant to asbestos it is likely that only one was the 'true cause' of the injury. Climate change, by contrast, is caused by the accumulation of greenhouse gases in the atmosphere, and 39