From Search to Signal: Dynamic Spillovers Between Biodiversity Attention and Climate Attention in South Africa

Biodiversity loss and climate change are often treated as a single environmental problem, yet it remains unclear whether they generate distinct forms of public attention. This paper addresses this gap by examining whether biodiversity-related attention constitutes an independent signal or is largely absorbed within climate attention. We construct a South African Biodiversity Attention Index (SABAI) using monthly Google Trends data from 2004--2025 based on a 242-term dictionary that combines global biodiversity concepts with South African ecological terminology. SABAI is analysed jointly with the Climate Attention Index for South Africa (CAI-SA) within a time-varying parameter vector autoregressive (TVP-VAR) connectedness framework. The results show that biodiversity attention and climate attention are positively related but not interchangeable. Biodiversity attention acts as the dominant net transmitter of shocks for most of the sample, while climate attention is generally the net receiver. Crucially, total connectedness declines over time, providing clear evidence that the two attention series are becoming increasingly distinct rather than more integrated. The dynamics of SABAI further suggest that biodiversity attention responds to identifiable biodiversityrelated events. These findings establish that biodiversity attention captures an independent and evolving dimension of environmental concern. The results challenge the common practice of treating biodiversity loss as a secondary component of climate change and highlight the need to analyse biodiversity dynamics in their own right.