Large scale volcanism has played a critical role in the long-term habitability of Earth and possibly Venus. Large Igneous Provinces (LIPs) are in fact the cause of most major extinction events in Earth’s history, contrary to the popular belief about the devastation from large bolides. We examine the timing of Large Igneous Provinces (LIPs) through Earth’s history  to estimate the likelihood of nearly simultaneous events that could drive a planet into an extreme moist or runaway greenhouse, quenching subductive plate tectonics. Such events would end volatile cycling and may have driven Venus from a cool temperate state into the heat-death we see today. Using the Earth’s LIP record  we have found that LIP events are distributed randomly throughout the past 3 billion years. A conservative estimate of the rate of LIPs in a random history statistically the same as Earth’s, pairs and triplets of LIPs closer in time than 0.1-1 million years are likely. This simultaneity threshold is significant to the extent that it is less than the time over which environmental effects have been shown to persist, for example in the Siberian Traps record [2,3]. With the recent mission selections of VERITAS and EnVision it may be possible for their high resolution radar maps to distinguish LIPs in the surface record we can see today on Venus.
 Ernst, R.E. et al. (2021). Large Igneous Province Record Through Time and Implications for Secular Environmental Changes and Geological Time-Scale Boundaries. In: Ernst, R.E., Dickson, A.J., Bekker, A. (eds.) Large Igneous Provinces: A Driver of Global Environmental and Biotic Changes. AGU Geophysical Monograph 255 (pp. 3-26).
 Burgess, S.D. et al. (2014). High-precision timeline for Earth’s most severe extinction. Proceedings of the National Academy of Sciences, 111: 3316–3321 [correction 2014, 111: 5050].
 Burgess, S.D. & Bowring, S.A. (2015). High-precision geochronology confirms voluminous magmatism before, during and after Earth’s most severe extinction. Sci. Adv. 1 (7), e1500470. http://dx.doi.org/10.1126/sciadv.1500470.