Denying bogus skepticism in climate change and tourism research

This final response to the two climate change denial papers by Shani and Arad further highlights the inaccuracies, misinformation and errors in their commentaries. The obfuscation of scientific research and the consensus on anthropogenic climate change may have significant long-term negative consequences for better understanding the implications of climate change and climate policy for tourism and create confusion and delay in developing and implementing tourism sector responses

Exact joint likelihood of pseudo-Cℓ estimates from correlated Gaussian cosmological fields

We present the exact joint likelihood of pseudo-$C_\ell$ power spectrum estimates measured from an arbitrary number of Gaussian cosmological fields. Our method is applicable to both spin-0 fields and spin-2 fields, including a mixture of the two, and is relevant to Cosmic Microwave Background, weak lensing and galaxy clustering analyses. We show that Gaussian cosmological fields are mixed by a mask in such a way that retains their Gaussianity, without making any assumptions about the mask geometry. We then show that each auto- or cross-pseudo-$C_\ell$ estimator can be written as a quadratic form, and apply the known joint distribution of quadratic forms to obtain the exact joint likelihood of a set of pseudo-$C_\ell$ estimates in the presence of an arbitrary mask. Considering the polarisation of the Cosmic Microwave Background as an example, we show using simulations that our likelihood recovers the full, exact multivariate distribution of $EE$, $BB$ and $EB$ pseudo-$C_\ell$ power spectra. Our method provides a route to robust cosmological constraints from future Cosmic Microwave Background and large-scale structure surveys in an era of ever-increasing statistical precision.Comment: 17 pages, 7 figures. Updated to match accepted versio

Sufficiency of a Gaussian power spectrum likelihood for accurate cosmology from upcoming weak lensing surveys

We investigate whether a Gaussian likelihood is sufficient to obtain accurate parameter constraints from a Euclid-like combined tomographic power spectrum analysis of weak lensing, galaxy clustering and their cross-correlation. Testing its performance on the full sky against the Wishart distribution, which is the exact likelihood under the assumption of Gaussian fields, we find that the Gaussian likelihood returns accurate parameter constraints. This accuracy is robust to the choices made in the likelihood analysis, including the choice of fiducial cosmology, the range of scales included, and the random noise level. We extend our results to the cut sky by evaluating the additional non-Gaussianity of the joint cut-sky likelihood in both its marginal distributions and dependence structure. We find that the cut-sky likelihood is more non-Gaussian than the full-sky likelihood, but at a level insufficient to introduce significant inaccuracy into parameter constraints obtained using the Gaussian likelihood. Our results should not be affected by the assumption of Gaussian fields, as this approximation only becomes inaccurate on small scales, which in turn corresponds to the limit in which any non-Gaussianity of the likelihood becomes negligible. We nevertheless compare against N-body weak lensing simulations and find no evidence of significant additional non-Gaussianity in the likelihood. Our results indicate that a Gaussian likelihood will be sufficient for robust parameter constraints with power spectra from Stage IV weak lensing surveys.Comment: 15 pages, 19 figures, matches version accepted by MNRA

No time for smokescreen skepticism: A rejoinder to Shani and Arad

Shani and Arad (2014) claimed that tourism scholars tend to endorse the most pessimistic assessments regarding climate change, and that anthropogenic climate change was a “fashionable” and “highly controversial scientific topic”. This brief rejoinder provides the balance that is missing from such climate change denial and skepticism studies on climate change and tourism. Recent research provides substantial evidence that reports on anthropogenic climate change are accurate, and that human-induced greenhouse gas emissions, including from the tourism industry, play a significant role in climate change. Some positive net effects may be experienced by some destinations in the short-term, but in the long-term all elements of the tourism system will be impacted. The expansion of tourism emissions at a rate greater than efficiency gains means that it is increasingly urgent that the tourism sector acknowledge, accept and respond to climate change. Debate on tourism-related adaptation and mitigation measures is to be encouraged and welcomed. Climate change denial is not