[Paper Review] A possible explanation for Earth's climatic changes in the past few million years

W. Woelfli, W. Baltensperger|ArXiv.org|Jul 21, 1999

Geology and Paleoclimatology Research25 references3 citations

TL;DR

This paper proposes that a hypothetical massive planet, designated 'Z', on a highly eccentric orbit around the Sun, caused significant climatic shifts on Earth over the past 3.2 million years by gravitationally perturbing a gas cloud, leading to pole shifts and triggering major climate changes. The last such event, around 11,500 years ago, is suggested to have ended the last Ice Age, offering an alternative explanation to the Milankovitch theory for observed climatic patterns.

ABSTRACT

The astronomical theory of Milankovitch relates the changes of Earth' past climate to variations in insolation caused by oscillations of the orbital parameters. However, this theory has problems to account for some major observed phenomena of the past few million years. Here, we present an alternative explanation for these phenomena. It is based on the idea that the solar system until quite recently contained an additional massive object of planetary size. This object, called Z, is assumed to have moved on a highly eccentric orbit bound to the sun. It influenced Earth's climate through a gas cloud of evaporated material. Calculations show that more than once during the last 3.2 Myr it even approached the Earth close enough to provoke a significant shift of the geographic position of the poles. The last of these shifts terminated Earth's Ice Age epoch about 11.5 kyr ago. The origin and fate of Z is also discussed.

Motivation & Objective

• To address inconsistencies in the Milankovitch astronomical theory regarding Earth's climatic changes over the past few million years.
• To investigate whether an undiscovered massive planet (Z) on a highly eccentric orbit could explain abrupt climatic shifts and polar wander events.
• To model the gravitational and dynamical effects of such a planet on Earth's climate system and axial orientation.
• To propose a mechanism linking planetary perturbations to the termination of the last Ice Age around 11,500 years ago.

Proposed method

• Assumes the existence of a massive, planet-sized object (Z) in a highly eccentric orbit bound to the Sun.
• Models gravitational interactions between Z and Earth, particularly during close approaches.
• Analyzes the influence of evaporated material from Z forming a transient gas cloud that could affect Earth's climate and rotational dynamics.
• Uses orbital mechanics and celestial dynamics to calculate the timing and effects of Z's closest approaches to Earth over the past 3.2 million years.
• Evaluates the potential for Z to induce significant shifts in Earth's geographic poles during these close encounters.
• Considers the origin and eventual fate of Z, including possible ejection or collision scenarios.

Experimental results

Research questions

• RQ1 Could the presence of a massive, unseen planet on a highly eccentric orbit explain major climatic shifts in Earth's recent history?
• RQ2 What physical mechanisms could link planetary perturbations to abrupt changes in Earth's axial tilt and pole position?
• RQ3 How frequently did such a planet (Z) come close enough to Earth to trigger significant climatic events over the past 3.2 million years?
• RQ4 What evidence supports the idea that the last Ice Age ended due to a pole shift induced by Z's gravitational influence?
• RQ5 What are the plausible origins and ultimate fates of such a hypothetical planet Z?

Key findings

• The model predicts that the hypothetical planet Z approached Earth closely enough on multiple occasions over the past 3.2 million years to induce significant shifts in Earth's geographic poles.
• The last such close approach occurred approximately 11,500 years ago, coinciding with the termination of the last Ice Age.
• Gravitational interactions with Z and its associated evaporated gas cloud could have altered Earth's climate by modifying insolation patterns and axial dynamics.
• The timing and frequency of these close approaches are consistent with observed climatic transitions in the geological record.
• The model provides a physical mechanism for pole shifts not accounted for by the standard Milankovitch theory.
• The origin of Z is hypothesized to be from a planetary system that formed in the solar system's early history, with its eventual ejection or collision explaining its current absence.